Editing Goguryeo (section)

==History==
===Origins===
[[File:Goguryeo_armor.jpg|thumb|left|300px|Goguryeo [[Cataphract]](개마무사/鎧馬武士)]]
The earliest record of the name of Goguryeo can be traced to geographic monographs in the ''[[Book of Han]]'' and is first attested as the name of one of the subdivisions of the [[Xuantu Commandery]], established along the trade routes within the [[Yalu River|Amnok river]] basin following the destruction of [[Gojoseon]] in 113 BC.{{sfn|Beckwith|2007|p=33}} The American historian [[Christopher I. Beckwith|Christopher Beckwith]] offers the alternative proposal that the Guguryeo people were first located in or around [[Liaoxi Commandery|Liaoxi]] (western [[Liaoning]] and parts of [[Inner Mongolia]]) and later migrated eastward, pointing to another account in the ''Book of Han''.{{Citation needed|date=October 2023}} The early Goguryeo tribes from whom the administrative name is derived were located close to or within the area of control of the Xuantu Commandery.<ref name="Barnes">{{cite book |last1=Barnes |first1=Gina L |title=State Formation in Korea: Historical and Archaeological Perspectives |date=2001 |isbn=978-0700713233 |page=22 |publisher=Psychology Press |url={{GBurl|id=yK8m1XiEKz0C|p=22}} |access-date=25 February 2021}}</ref><ref name="Mohan">{{cite book |last1=Mohan |first1=Pankaj |editor1-last=MacKenzie |editor1-first=John M |title=The Encyclopedia of Empire |date=2016 |publisher=Wiley |url=https://onlinelibrary.wiley.com/doi/pdf/10.1002/9781118455074.wbeoe104 |access-date=25 February 2021 |chapter=Goguyreo|doi=10.1002/9781118455074.wbeoe104 |isbn=978-1118455074 }}</ref> Its tribal leaders also appeared to have held the ruler title of "marquis" over said nominal [[Gaogouli County|Gaogouli/Goguryeo county]].<ref>{{cite journal |last1=Zhang |first1=Xuefeng |date=2010 |title=The Formation of East Asian World during the 4th and 5th Centuries: A Study Based on Chinese Sources |url=https://brill.com/view/journals/fhic/5/4/article-p525_3.xml |journal=Frontiers of History in China |volume=5 |issue=4 |pages=528–529 |doi=10.1007/s11462-010-0110-z |s2cid=154743659}}</ref> The collapse of the first Xuantu Commandery in 75 BC is generally attributed to the military actions of the Goguryeo natives.<ref>"In the year 11 AD, he ([[Wang Mang]]) ordered the Koguryo people to attack the Hsiung-nu. When they refused, their ruler was murdered by the Han governor of Liao-hsi and 'so the Maek [i.e., Koguryo] people raided the frontier even more'."</ref><ref>先是，莽發高句驪兵，當伐胡，不欲行，郡強迫之，皆亡出塞，因犯法為寇。遼西大尹田譚追擊之，為所殺。州郡歸咎於高句驪侯騶。[...] 莽不尉安，穢貉遂反，詔尤擊之。尤誘高句驪侯騶至而斬焉，傳首長安。[...] 於是貉人愈犯邊，東北與西南夷皆亂云。<br />''Book of Han'', Chapter 99.</ref> In the ''[[Old Book of Tang]]'' (945), it is recorded that [[Emperor Taizong of Tang|Emperor Taizong]] refers to Goguryeo's history as being some 900 years old. According to the 12th-century ''[[Samguk sagi]]'' and the 13th-century ''[[Samguk yusa]]'', a prince from the Buyeo kingdom named Jumong fled after a power struggle with other princes of the court{{sfn|Byington|2003|p= 234}}{{full citation needed|date=January 2023}} and founded Goguryeo in 37 BC in a region called [[Jolbon|Jolbon Buyeo]], usually thought to be located in the middle [[Yalu River|Amnok/Yalu]] and [[Hun River (Yalu River tributary)|Hun River]] basin.

[[Samguk sagi|The Samguk Sagi]], a text from the 12th century in [[Goryeo]], claims that Goguryeo was founded in 37 BC, but today the date of the dynasty's foundation is in ''doubt'', as ''[[Archaeology|archaeological]] evidence'' suggests that ''Goguryeo was founded before [[Silla]]'', and four things support this:

# [[Kim Pu-sik]] was a 12th-century historian and author of the ''[[Samguk sagi]]'' (History of the Three Kingdoms). Since ''he was a descendant of the Silla royal family'', it is likely that he distorted history to show the superiority of his ancestor, Silla, and this is undeniable.<ref>{{Cite web |date=2018-02-13 |script-title=ko:고구려 건국연대를 아시나요? |url=http://www.minplusnews.com/news/articleView.html?idxno=4581 |access-date=2024-12-16 |website=현장언론 민플러스 |language=ko}}</ref>
# Since [[Kim Pu-sik]] wrote the History of the Three Kingdoms at least 5 centuries after the events of the Three Kingdoms and was not an eyewitness to the events of that era, his book is considered a [[secondary source]] and cannot be considered a [[primary source]] alone.<ref>{{Citation |last=Jeong  |first=Gu-bok |author-mask=Jeong Gu-bok (정구복) |script-title=ko:김부식 (金富軾) |script-work=ko:한국민족문화대백과사전 |trans-work=Encyclopedia of Korean Culture |url=https://encykorea.aks.ac.kr/Article/E0009275 |access-date=2024-12-16 |publisher=Academy of Korean Studies |language=ko}}</ref>
# The age of Goguryeo in the [[Samguk sagi|Samguk Sagi]] contradicts what is inscribed in [[Gwanggaeto Stele|Gwanggaeto the Great's stele]] (which is a [[primary source]]). [[Gwanggaeto the Great]]'s stele states that Goguryeo is ''900 years old'', but the Samguk Sagi mentions Goguryeo as a dynasty that lasted 705 years.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=udcKRwqkDRo |script-title=ko:환단고기가 밝히는 고구려 900년 역사의 완전한 복원 3가지, 태조 해모수, 해모수의 고향이름이 고구려, 그래서 고주몽이 북부여에서 고구려로 바꿈 |date=2018-03-15 |last=환단고기북콘서트STB |access-date=2024-12-16 |via=YouTube}}</ref><ref>{{Cite web |title=169. The sovereignty over South Korea belongs to Japan!? —Countermeasures against South Korea regarding to the "Takeshima Issue," Part 2 |url=http://teikoku-denmo.jp/en/history/kohtaioh-hi.html |access-date=2024-12-16 |website=teikoku-denmo.jp}}</ref><ref>{{Cite web |title=Complex of Koguryo Tombs |url=https://whc.unesco.org/en/list/1091/#:~:text=About%20100%20out%20of%20more,Democratic%20People's%20Republic%20of%20Korea. |access-date=2024-12-17 |website=whc.unesco.org}}</ref><ref>{{Cite web |date=2012-04-23 |script-title=ko:삼국사기 고구려 본기 제 28대 보장왕 (48) |url=https://cdh571.tistory.com/m/1096 |access-date=2024-12-17 |website=역사, 경제 글방 |language=ko}}</ref><ref>{{Cite web |script-title=ko:한문화중심채널 STB상생방송 - 900년 고구려(고고리) |url=https://www.stb.co.kr/?m=bbs&bid=stbfree&p=101&uid=1402 |access-date=2024-12-17 |website=www.stb.co.kr |language=ko}}</ref><ref>{{Cite web |script-title=ko:창세역사 성인열전 {{!}} 천하 사방에 다물多勿의 기상을 펼친 고구려 광개토태왕, 고담덕(上) :: 증산도 월간개벽 |url=https://www.greatopen.net/gb/article/view?id=7499 |access-date=2024-12-17 |website=www.greatopen.net |language=ko}}</ref><ref>{{Cite web |script-title=ko:카카오TV |url=https://tv.kakao.com/m/channel/2881457/cliplink/375618135?act=related_clip |access-date=2024-12-17 |website=tv.kakao.com}}</ref><ref>{{Cite web |date=2008-01-30 |script-title=ko:[플러스 코리아] 고구려 사직은 700년인가 900년인가?.. |url=https://m.pluskorea.net/9017 |access-date=2024-12-17 |website=플러스 코리아(Plus Korea) |language=ko}}</ref><ref>{{Cite web |date=2023-02-06 |script-title=ko:900년 고구려 38년 수나라, 누가 지배자인가 : 재외동포신문방송편집인협회 |url=https://gkjournal.org/30/?q=YToyOntzOjEyOiJrZXl3b3JkX3R5cGUiO3M6MzoiYWxsIjtzOjQ6InBhZ2UiO2k6OTU7fQ==&bmode=view&idx=14148634&t=board |access-date=2024-12-17 |website=gkjournal.org |language=ko}}</ref>
# Also, the [[Old Book of Tang]] (945), a [[primary source]], written by ''[[Emperor Taizong of Tang|Li Shimin]]'' ([[Emperor Taizong of Tang|Taizong]]), mentions that Goguryeo is ''about 900 years old''.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=udcKRwqkDRo |script-title=ko:환단고기가 밝히는 고구려 900년 역사의 완전한 복원 3가지, 태조 해모수, 해모수의 고향이름이 고구려, 그래서 고주몽이 북부여에서 고구려로 바꿈 |date=2018-03-15 |last=환단고기북콘서트STB |access-date=2024-12-16 |language=ko |via=YouTube}}</ref>

In 75 BC, a group of [[Yemaek]] who may have originated from Goguryeo made an incursion into China's [[Xuantu Commandery]] west of the Yalu.{{sfn|Byington|2003|p=194}}{{full citation needed|date=January 2023}} The first mention of Goguryeo as a group label associated with [[Yemaek]] tribes is a reference in the ''Han Shu'' that discusses a Goguryeo revolt in 12 AD, during which they broke away from the influence of the Xuantu Commandery.{{sfn|Byington|2003|p=233}}{{full citation needed|date=January 2023}}

According to Book 37 of the ''[[Samguk sagi]]'', Goguryeo originated north of [[Ancient Chinese states|ancient China]], then gradually moved east to the side of Taedong River.<ref>Book 37 of Samguk sagi Monographs recorded: 高句麗始居中國北地，則漸東遷于浿水之側</ref> At its founding, the Goguryeo people are believed to be a blend of people from Buyeo and Yemaek, as leadership from Buyeo may have fled their kingdom and integrated with existing Yemaek chiefdoms.{{sfn|Aikens|1992|pp=191–196}} The ''[[Records of the Three Kingdoms]]'', in the section titled "Accounts of the Eastern Barbarians", implied that Buyeo and the Yemaek people were ethnically related and spoke a similar language.<ref>{{cite book|last1=De Bary|first1=Theodore|last2=Peter H.|first2=Lee|title=Sources of Korean Tradition|year=2000|publisher=Columbia University Press|isbn=978-0231120319|pages=7–11}}</ref>

Chinese people were also in Gorguyeo.{{Citation needed|date=October 2023}} Book 28 of Samguk sagi stated that "many people of China fled [to] [[Names of Korea#Sobriquets of Korea|East of the Sea]] due to the chaos of war by Qin and Han".<ref>Book 28 of Samguk sagi: Baekje's Records Volume 6: 「秦、漢亂離之時，中國人多竄海東。」</ref> Later Han dynasty established the Four Commanderies, and in 12 AD Goguryeo made its first attack on the Xuantu Commandery.<ref>Book 13 of Samguk sagi Goguryeo's Records：秋八月，王命鳥伊烏伊、摩離，領兵二萬，西伐梁貊，滅其國，進兵襲取漢高句麗縣。(縣屬玄菟郡)"</ref> The population of [[Xuantu Commandery]] was about 221,845 in 2 AD, and they lived in the commandery's three counties of Gaogouli, Shangyintai, and Xigaima.<ref>Book of Han Volume 28 Part 2 玄菟郡，戶四萬五千六，口二十二萬一千八百四十五。縣三：高句驪，上殷台，西蓋馬。[[:s:zh:漢書/卷028下|Wikisource: the Book of Han, volume 28-2]]</ref> Later on, Goguryeo gradually annexed all the [[Four Commanderies of Han]] during its expansion.<ref>Book of the Later Han Volume 85 Treatise on the Dongyi</ref>

Both Goguryeo and [[Baekje]] shared founding myths and originated from [[Buyeo]].<ref>{{cite book|last1=The National Folk Museum of Korea (South Korea)|title=Encyclopedia of Korean Folk Literature: Encyclopedia of Korean Folklore and Traditional Culture Vol. III|date=2014|publisher=길잡이미디어|isbn=978-8928900848|page=41|url={{GBurl|id=DsR3BgAAQBAJ|p=41}}|access-date=10 September 2017|language=en}}</ref>

===Jumong and the foundation myth===
{{main|Jumong}}
[[File:Goguryeo moon.jpg|thumb|200px|left|Image of Dalshin from the Goguryeo-era Ohoe Tomb 4.]]

The earliest mention of Jumong is in the 4th-century [[Gwanggaeto Stele]]. Jumong is the modern Korean transcription of the [[hanja]] {{linktext|朱蒙}} ''Jumong'', {{linktext|鄒牟}} ''Chumo'', or {{linktext|仲牟}} ''Jungmo''.

The Stele states that Jumong was the first king and ancestor of Goguryeo and that he was the son of the prince of Buyeo and daughter of [[Habaek]] ({{Korean|하백|河伯}}), the god of the [[Amnok River]] or, according to an alternative interpretation, the sun god Haebak ({{Korean|해밝}}).<ref name="Sources of Korean Tradition">{{cite book|last1=De Bary|first1=Theodore|last2=Peter H.|first2=Lee|title=Sources of Korean Tradition|publisher=Columbia University Press|isbn=978-0231120319|pages=24–25|url={{GBurl|id=kWYCxE3plWkC|p=24}}|year=1997}}</ref><ref>{{Cite book|title=Doosan Encyclopedia 유화부인 柳花夫人|publisher=[[Doosan Encyclopedia]]|url=http://terms.naver.com/entry.nhn?docId=1185444&mobile&cid=40942&categoryId=33375}}</ref><ref name="Doosan Encyclopedia">{{Cite book|title=Doosan Encyclopedia 하백 河伯|publisher=[[Doosan Encyclopedia]]|url=http://terms.naver.com/entry.nhn?docId=1160526&cid=40942&categoryId=31541&mobile}}</ref><ref name="Encyclopedia of Korean Culture">{{Cite book|title=Encyclopedia of Korean Culture 하백 河伯|publisher=[[Encyclopedia of Korean Culture]]|url=http://terms.naver.com/entry.nhn?docId=531903&cid=46620&categoryId=46620&mobile}}</ref><ref>{{cite web|last1=조현설|script-title=ko:유화부인|url=http://folkency.nfm.go.kr/kr/topic/%EC%9C%A0%ED%99%94%EB%B6%80%EC%9D%B8/5387|website=[[Encyclopedia of Korean Folk Culture]]|publisher=[[National Folk Museum of Korea]]|access-date=30 April 2018}}</ref> The ''[[Samguk sagi]]'' and ''[[Samguk yusa]]'' paint additional detail and names Jumong's mother as [[Lady Yuhwa|Yuhwa]] ({{Korean|유화|柳花}}).<ref name="Sources of Korean Tradition"/><ref name="Doosan Encyclopedia"/><ref name="Encyclopedia of Korean Culture"/> Jumong's biological father was said to be a man named [[Hae Mo-su of Buyeo|Haemosu]] who is described as a "strong man" and "a heavenly prince."<ref>Ilyon, "Samguk yusa", Yonsei University Press, p. 45</ref> The river god chased Yuhwa away to the Ubal River ({{korean|hanja=優渤水|hangul=우발수}}) due to her pregnancy, where she met and became the concubine of [[Geumwa of Dongbuyeo|Geumwa]].

Jumong was well known for his exceptional [[archery]] skills. Eventually, Geumwa's sons became jealous of him, and Jumong was forced to leave [[Eastern Buyeo]].<ref>Ilyon, "Samguk yusa", p. 46</ref> The Stele and later Korean sources disagree as to which Buyeo Jumong came from. The Stele says he came from [[Buyeo]] and the ''Samguk yusa'' and ''Samguk sagi'' say he came from Eastern Buyeo. Jumong eventually made it to [[Jolbon]], where he married [[Soseono]], daughter of its ruler. He subsequently became king himself, founding Goguryeo with a small group of his followers from his native country.

A traditional account from the "Annals of Baekje" section in the ''Samguk sagi'' says that Soseono was the daughter of Yeon Tabal, a wealthy influential figure in Jolbon<ref>[http://100.empas.com/dicsearch/pentry.html?s=K&i=273624 Encyclopedia of Korean Culture] {{in lang|ko}}</ref> and married to Jumong. However, the same source officially states that the king of Jolbon gave his daughter to Jumong, who had escaped with his followers from Eastern Buyeo, in marriage. She gave her husband, Jumong, financial support<ref name="proper">[https://archive.today/20121209100935/http://100.naver.com/100.nhn?docid=828500 Doosan Encyclopedia Online] {{in lang|ko}}</ref> in founding the new statelet, Goguryeo. After [[Yuri of Goguryeo|Yuri]], son of Jumong and his first wife, Lady Ye, came from Dongbuyeo and succeeded Jumong, she left Goguryeo, taking her two sons [[Biryu]] and [[Onjo of Baekje|Onjo]] south to found their own kingdoms, one of which was [[Baekje]].

Jumong's given surname was "Hae" ({{korean|hanja=解|hangul=해}}), the name of the Buyeo rulers. According to the ''Samguk yusa'', Jumong changed his surname to "Go" ({{korean|hanja=高|hangul=고}}) in conscious reflection of his divine parentage.<ref>Ilyon, "Samguk yusa", pp. 46–47</ref> Jumong is recorded to have conquered the tribal states of Biryu ({{korean|hanja=沸流國|hangul=비류국}}) in 36 BC, Haeng-in ({{korean|hanja=荇人國|hangul=행인국}}) in 33 BC, and Northern [[Okjeo]] in 28 BC.<ref>《三国史记》："六年 秋八月 神雀集宫庭 冬十月 王命乌伊扶芬奴 伐太白山东南人国 取其地为城邑。十年 秋九月 鸾集于王台 冬十一月 王命扶尉 伐北沃沮灭之 以其地为城邑"</ref><ref name="mygoguryeo" />

===Centralization and early expansion (mid-first century)===
Goguryeo developed from a league of various [[Yemaek]] tribes to an early state and rapidly expanded its power from their original basin of control in the [[Hun River (Yalu River tributary)|Hun River]] drainage. In the time of [[Taejodae of Goguryeo|Taejodae]] in 53 AD, five local tribes were reorganized into five centrally ruled districts. Foreign relations and the military were controlled by the king. Early expansion might be best explained by ecology; Goguryeo controlled territory in what is currently central and southern [[Manchuria]] and northern [[Korea]], which are both very mountainous and lacking in arable land. Upon centralizing, Goguryeo might have been unable to harness enough resources from the region to feed its population and thus, following historical [[Pastoralism|pastoralist]] tendencies, would have sought to raid and exploit neighboring societies for their land and resources. Aggressive military activities may have also aided expansion, allowing Goguryeo to exact tribute from their tribal neighbors and dominate them politically and economically.<ref>Gina L. Barnes, "State Formation in Korea", 2001 Curzon Press, p. 22 {{ISBN?}}</ref>

Taejo conquered the [[Okjeo]] tribes of what is now northeastern Korea as well as the [[Eastern Ye|Dongye]] and other tribes in Southeastern Manchuria and Northern Korea. From the increase of resources and manpower that these subjugated tribes gave him, Taejodae led Goguryeo in attacking the [[Four Commanderies of Han|Han Commanderies]] of [[Lelang Commandery|Lelang]] and [[Xuantu Commandery|Xuantu]] on the [[Korean Peninsula|Korean]] and [[Liaodong Peninsula|Liaodong]] peninsulas, becoming fully independent from them.<ref>Ki-Baik Lee, "A New History of Korea", 1984 Harvard University Press, p. 24 {{ISBN?}}</ref>

Generally, Taejodae allowed the conquered tribes to retain their chieftains, but required them to report to governors who were related to Goguryeo's royal line; tribes under Goguryeo's jurisdiction were expected to provide heavy tribute. Taejodae and his successors channeled these increased resources to continuing Goguryeo's expansion to the north and west. New laws regulated peasants and the aristocracy, as tribal leaders continued to be absorbed into the central aristocracy. Royal succession changed from fraternal to patrilineal, stabilizing the royal court.<ref>Ki-Baik Lee, "A New History of Korea", 1984, Harvard University Press, p. 36</ref>

The expanding Goguryeo kingdom soon entered into direct military contact with the [[Liaodong Commandery]] to its west. Around this time, Chinese warlord [[Gongsun Kang]] established the [[Daifang Commandery]] by separating the southern half from the Lelang commandery. Balgi, a brother of King [[Sansang of Goguryeo]], defected to Kang and asked for Kang's aid to help him take the throne of Goguryeo. Although Goguryeo defeated the first invasion and killed Balgi,<ref>{{cite news |title=History: King Sansang |url=https://world.kbs.co.kr/service/contents_view.htm?lang=e&menu_cate=history&id=&board_seq=4009&page=3&board_code=dynasty |access-date=30 August 2023 |agency=KBS |date=March 2015}}</ref> in 209, Kang invaded Goguryeo again, seized some of its territory and weakened Goguryeo.<ref>{{cite book|author=[[Chen Shou]]|title=Records of the Three Kingdoms|volume=30|url=https://zh.wikisource.org/wiki/%E4%B8%89%E5%9C%8B%E5%BF%97/%E5%8D%B730|quote=建安中，公孫康出軍擊之，破其國，焚燒邑落。拔奇怨爲兄而不得立，與涓奴加各將下戶三萬餘口詣康降，還住沸流水。}}</ref><ref>{{citation|last=de Crespigny|first=Rafe|year=2007|title=A Biographical Dictionary of Later Han to the Three Kingdoms|publisher=Brill|page=988}}</ref> Pressure from Liaodong forced Goguryeo to move their capital in the Hun River valley to the [[Yalu River]] valley near [[Wandu Mountain City|Hwando]].<ref>'Gina L. Barnes', "State Formation in Korea", 2001 Curzon Press, pp. 22–23'</ref>

===Goguryeo–Wei Wars===
{{Main|Goguryeo–Wei War}}

In the chaos following the fall of the [[Han dynasty]], the former Han commanderies had broken free of control and were ruled by various independent warlords. Surrounded by these commanderies, who were governed by aggressive warlords, Goguryeo moved to improve relations with the newly created dynasty of [[Cao Wei]] in China and sent tribute in 220. In 238, Goguryeo entered into a formal alliance with Wei [[Sima Yi's Liaodong campaign|to destroy the Liaodong commandery]].{{citation needed|date=January 2023}}

When Liaodong was finally conquered by Wei, cooperation between Wei and Goguryeo fell apart and Goguryeo attacked the western edges of Liaodong, which incited a Wei counterattack in 244. Thus, Goguryeo initiated the [[Goguryeo–Wei War]] in 242, trying to cut off Chinese access to its territories in Korea by attempting to take a Chinese fort. However, the Wei state responded by invading and defeated Goguryeo. The capital at Hwando was destroyed by Wei forces in 244.<ref>{{cite book |access-date=9 February 2012 |year=1996 |quote=Wei. In 242, under King Tongch'ŏn, they attacked a Chinese fortress near the mouth of the Yalu in an attempt to cut the land route across Liao, in return for which the Wei invaded them in 244 and sacked Hwando. |url = {{GBurl|id=tKTtAAAAMAAJ|q=244+sacked}} |edition=illustrated |isbn=978-0-7103-0532-9 |publisher=Kegan Paul International|title=A history of Korea |author=Charles Roger Tennant|author-link = Roger Tennant |page=22 }}</ref> It is said that [[Dongcheon of Goguryeo|Dongcheon]], with his army destroyed, fled for a while to the [[Okjeo]] state in the east.<ref>'Gina L. Barnes', "State Formation in Korea", 2001 Curzon Press, p. 23'</ref> Wei invaded again in 259 but was defeated at Yangmaenggok;<ref>{{cite book|last1=Injae|first1=Lee|last2=Miller|first2=Owen|last3=Jinhoon|first3=Park|last4=Hyun-Hae|first4=Yi|title=Korean History in Maps|publisher=Cambridge University Press|isbn=978-1107098466|page=30|url={{GBurl|id=46OTBQAAQBAJ|p=30}}|access-date=10 October 2016|language=en|date=2014}}</ref> according to the ''[[Samguk sagi]]'', [[Jungcheon of Goguryeo|Jungcheon]] assembled 5,000 elite cavalry and defeated the invading Wei troops, beheading 8,000 enemies.<ref>{{cite book|last=Kim Bu-sik|title=Samguk sagi|volume=17|quote=十二年冬十二月王畋于杜訥之谷魏將尉遲楷名犯長陵諱將兵來伐王簡精騎五千戰於梁貊之谷敗之斬首八千餘級}}</ref>

===Revival and further expansion (300 to 390)===
[[File:Tbridge10.jpg|thumb|220px|Seated [[buddhahood|buddhas]] and [[bodhisattva]]s from Wono-ri, Goguryeo.]]
[[File:Korean crown-01.jpg|thumb|right|220px|A gilt-bronze crown from Goguryeo believed to have once adorned the head of a [[bodhisattva]] image.]]

In only 70 years, Goguryeo rebuilt its capital [[Hwando]] and again began to raid the Liaodong, Lelang and Xuantu commanderies. As Goguryeo extended its reach into the [[Liaodong Peninsula]], the last [[Jin dynasty (265–420)|Chinese]] commandery at Lelang was conquered and absorbed by [[Micheon of Goguryeo|Micheon]] in 313, bringing the remaining northern part of the Korean peninsula into the fold.<ref>'Ki-Baik Lee', "A New History of Korea", 1984 Harvard University Press, page 20</ref> This conquest resulted in the end of Chinese rule over territory in the northern Korean peninsula, which had spanned 400 years.<ref name="Tennant">{{cite book|last1=Tennant|first1=Charles Roger|title=A History of Korea|publisher=Routledge|isbn=978-0710305329|page=22|url={{GBurl|id=Xn85nFTAX8EC|p=22}}|access-date=10 October 2016|language=en|quote=Soon after, the Wei fell to the Jin and Koguryŏ grew stronger, until in 313 they finally succeeded in occupying Lelang and bringing to an end the 400 years of China's presence in the peninsula, a period sufficient to ensure that for the next 1,500 it would remain firmly within the sphere of its culture. After the fall of the Jin in 316, the proto-Mongol Xianbei occupied the North of China, of which the Murong clan took the Shandong area, moved up to the Liao, and in 341 sacked and burned the Koguryŏ capital at Hwando. They took away some thousands of prisoners to provide cheap labour to build more walls of their own, and in 346 went on to wreak even greater destruction on Puyŏ, hastening what seems to have been a continuing migration of its people into the north-eastern area of the peninsula, but Koguryŏ, though temporarily weakened, would soon rebuild its walls and continue to expand.|year=1996}}</ref><ref>{{cite book|url={{GBurl|id=EazRC28tdIIC|p=3}}|title=Tracing Back the Radiance: Chinul's Korean Way of Zen|publisher=University of Hawaii Press|others=Translated by Robert E. Buswell|year=1991|isbn=978-0824814274|editor-last=Buswell|editor-first=Robert E.|edition=abridged|page=3|author=Chinul|access-date=22 April 2014}}</ref> From that point on, until the 7th century, territorial control of the peninsula would be contested primarily by the [[Three Kingdoms of Korea]].

Goguryeo met major setbacks and defeats during the reign of [[Gogugwon of Goguryeo|Gogukwon]] in the 4th century. In the early 4th century, the nomadic proto-Mongol [[Xianbei]] people occupied northern China;<ref name="Tennant" /> during the winter of 342, the Xianbei of [[Former Yan]], ruled by the [[Murong]] clan, attacked and destroyed Goguryeo's capital, Hwando, capturing 50,000 Goguryeo men and women to use as slave labor in addition to taking the Queen Dowager and Queen prisoner,<ref>{{cite book|title=Tracing Back the Radiance: Chinul's Korean Way of Zen|author=Chinul|editor-first=Robert E.|editor-last=Buswell|others=Translated by Robert E. Buswell|edition=abridged|year=1991|publisher=University of Hawaii Press|url={{GBurl|id=EazRC28tdIIC|p=4}}|page=4|isbn=978-0824814274|access-date=22 April 2014}}</ref> and forced Gogukwon to flee for a while. The Xianbei also devastated Buyeo in 346, accelerating Buyeo migration to the Korean peninsula.<ref name="Tennant" /> In 371, [[Geunchogo of Baekje]] killed Gogukwon in the [[Battle of Chiyang]] and sacked [[Pyongyang]], one of Goguryeo's largest cities.<ref name="World History P464">''Encyclopedia of World History'', Vol I, p. 464 Three Kingdoms, Korea, Edited by Marsha E. Ackermann, Michael J. Schroeder, Janice J. Terry, Jiu-Hwa Lo Upshur, Mark F. Whitters, {{ISBN|978-0-8160-6386-4}}.</ref>

[[Sosurim of Goguryeo|Sosurim]], who succeeded the slain Gogukwon, reshaped the nation's institutions to save it from a great crisis.<ref name="Sosurim">{{cite book|last1=Kim|first1=Jinwung|title=A History of Korea: From "Land of the Morning Calm" to States in Conflict|publisher=Indiana University Press|isbn=978-0253000781|page=34|url={{GBurl|id=QFPsi3IK8gcC|p=34}}|access-date=10 October 2016|language=en|date=2012}}</ref> Turning to domestic stability and the unification of various conquered tribes, Sosurim proclaimed new laws, embraced [[Buddhism]] as the state religion in 372, and established a national educational institute called the ''Taehak'' ({{korean|hanja=太學|hangul=태학}}).<ref name="Lee">{{cite book|last1=Yi|first1=Ki-baek|title=A New History of Korea|publisher=Harvard University Press|isbn=978-0674615762|pages=38–40|url={{GBurl|id=g2mdVwXpMzwC|p=38}}|access-date=11 October 2016|language=en|year=1984}}</ref> Due to the defeats that Goguryeo had suffered at the hands of the Xianbei and [[Baekje]], Sosurim instituted military reforms aimed at preventing such defeats in the future.<ref name="Sosurim" /><ref name="William E. Henthorn' page 34">'William E. Henthorn', "A History of Korea", 1971 Macmillan Publishing Co., p. 34</ref> Sosurim's internal arrangements laid the groundwork for Gwanggaeto's expansion.<ref name="Lee" /> His successor and the father of [[Gwanggaeto the Great]], [[Gogugyang of Goguryeo|Gogukyang]], invaded [[Later Yan]], the successor state of Former Yan, in 385 and Baekje in 386.<ref>{{cite web|script-title=ko:국양왕|url=http://www.culturecontent.com/content/contentView.do?search_div=CP_THE&search_div_id=CP_THE004&cp_code=rp0703&index_id=rp07031366&content_id=rp070313660001&search_left_menu=|website=KOCCA|publisher=Korea Creative Content Agency|access-date=11 October 2016}}</ref><ref>{{cite web|title=Kings and Queens of Korea|url=http://world.kbs.co.kr/english/program/program_dynasty_detail.htm?No=10039591|website=[[KBS World Radio]]|access-date=10 October 2016|archive-date=24 October 2016|archive-url=https://web.archive.org/web/20161024215257/http://world.kbs.co.kr/english/program/program_dynasty_detail.htm?No=10039591|url-status=dead}}</ref>

Goguryeo used its military to protect and exploit semi-nomadic peoples, who served as vassals, foot soldiers, or slaves, such as the Okjeo people in the northeast end of the Korean peninsula, and the [[Mohe people]] in [[Manchuria]], who would later become the [[Jurchen people|Jurchens]].<ref name="Tennant21">{{cite book|last1=Tennant|first1=Charles Roger|title=A History of Korea|publisher=Routledge|isbn=978-0710305329|pages=21–22|url={{GBurl|id=Xn85nFTAX8EC|p=21}}|access-date=10 October 2016|language=en|year=1996}}</ref>

===Zenith of Goguryeo's Power (391 to 531 AD)===
[[File:Rubbing of the Gwanggaeto S.jpg|thumb|right|150px|Detail of a rubbing of the [[Gwanggaeto Stele]] (414 AD), one of the few surviving records made by Goguryeo, written in [[Classical Chinese]].]]
[[File:Kevsunblush2.JPG|thumb|220px|right|A royal tomb, located in [[Ji'an, Jilin]], China, was built by the Goguryeo Kingdom.]]

Goguryeo experienced a golden age under [[Gwanggaeto the Great]] and his son [[Jangsu of Goguryeo|Jangsu]].<ref>{{cite book|last1=Yi|first1=Hyŏn-hŭi|last2=Pak|first2=Sŏng-su|last3=Yun|first3=Nae-hyŏn|title=New history of Korea|year=2005|publisher=Jimoondang|isbn=978-8988095850|page=201|url={{GBurl|id=KO8MAQAAMAAJ}}|language=en}} "He launched a military expedition to expand his territory, opening the golden age of Goguryeo."</ref><ref>{{cite book|last1=Hall|first1=John Whitney|title=The Cambridge History of Japan|year=1988|publisher=Cambridge University Press|isbn=978-0521223522|page=362|url={{GBurl|id=A3_6lp8IOK8C|q=%22The+reign+of+King+Kwanggaet%27o+is+thought+of+as+Koguryo%27s+golden+age+of+political+might+and+Buddhist+splendor.%22}}|access-date=29 July 2016|language=en}}</ref><ref>{{cite book|last1=Embree|first1=Ainslie Thomas|title=Encyclopedia of Asian history|year=1988|publisher=Scribner|isbn=978-0684188997|page=324|url={{GBurl|id=LtwpAQAAMAAJ|q=%22Nevertheless%2C+the+reigns+of+Kwanggaet%27o+and+his+successor+Changsu+%28413-491%29+constituted+the+golden+age+of+Koguryo.%22}}|access-date=29 July 2016|language=en}}</ref><ref>{{cite book|last1=Cohen|first1=Warren I.|title=East Asia at the Center: Four Thousand Years of Engagement with the World|date=2000|publisher=Columbia University Press|isbn=978-0231502511|page=50|url={{GBurl|id=Okjd2rDwb8IC|q=%22Koguryo%27s+Golden+Age%22}}|access-date=29 July 2016|language=en}}</ref> During this period, Goguryeo territories included three fourths of the [[Korean Peninsula]], including what is now [[Seoul]], almost all of Manchuria,<ref name="Jinwung">{{cite book|last1=Kim|first1=Jinwung|title=A History of Korea: From "Land of the Morning Calm" to States in Conflict|date=2012|publisher=Indiana University Press|location=Bloomington|isbn=978-0253000781|pages=35–36|url={{GBurl|id=QFPsi3IK8gcC|p=35}}|access-date=15 July 2016|language=en}}</ref> and parts of [[Inner Mongolia]].<ref>{{cite book|last1=Tudor|first1=Daniel|title=Korea: The Impossible Country: The Impossible Country|date=2012|publisher=Tuttle Publishing|isbn=978-1462910229|url={{GBurl|id=BA_QAgAAQBAJ|q=Inner+Mongolia}}|access-date=15 July 2016|language=en}}</ref> There is archaeological evidence that Goguryeo's maximum extent lay even further west in now [[Mongolia]], based on discoveries of [[Korean fortress|Goguryeo fortress]] ruins in Mongolia.<ref>{{cite web|last1=김운회|script-title=ko:한국과 몽골, 그 천년의 비밀을 찾아서|url=http://www.pressian.com/news/article.html?no=113599|website=[[Pressian]]|date=4 February 2014|publisher=Korea Press Foundation|access-date=11 October 2016}}</ref>{{Unreliable source?|date=June 2023}}<ref>{{cite web|last1=成宇濟|script-title=ko:고고학자 손보기 교수|url=http://www.sisapress.com/journal/articlePrint/99094|website=[[Sisa Journal]]|access-date=11 October 2016|archive-url=https://web.archive.org/web/20180313031650/http://www.sisapress.com/journal/articlePrint/99094|archive-date=13 March 2018|url-status=dead}}</ref>{{Unreliable source?|date=June 2023}}<ref>{{cite web|script-title=ko:[초원 실크로드를 가다](14)초원로가 한반도까지|url=http://news.khan.co.kr/kh_travel/khan_art_view.html?artid=200905061508575|website=[[Kyunghyang Shinmun]]|date = 19 August 2009|access-date=11 October 2016}}</ref>

Gwanggaeto the Great (r. 391–412) was a highly energetic [[Taewang|emperor]] who is remembered for his rapid military expansion of the realm.<ref name="William E. Henthorn' page 34" /> He instituted the era name of ''Yeongnak'' or ''Eternal Rejoicing'', affirming that Goguryeo was on equal standing with the dynasties in the Chinese mainland.<ref name="Jinwung" /><ref name="Lee" /><ref name="Djun">{{cite book|last1=Kim|first1=Djun Kil|title=The History of Korea|edition=2nd|date= 2014|publisher=ABC-CLIO|isbn=978-1610695824|page=32|url={{GBurl|id=IgxvBAAAQBAJ|p=32}}|access-date=4 August 2016|language=en}}</ref> Gwanggaeto conquered 64 walled cities and 1,400 villages during his campaigns.<ref name="Lee" /><ref name="Jinwung" /> To the west, he destroyed neighboring [[Khitan people|Khitan]] tribes and invaded [[Later Yan]], conquering the entire [[Liaodong Peninsula]];<ref name="Lee" /><ref name="Jinwung" /><ref name="Djun" /> to the north and east, he annexed much of [[Buyeo]] and conquered the [[Sushen]], who were [[Tungusic peoples|Tungusic]] ancestors of the [[Jurchen people|Jurchens]] and [[Manchu people|Manchus]];<ref>{{cite book|last1=Walker|first1=Hugh Dyson|title=East Asia: A New History|date=2012|publisher=AuthorHouse|isbn=978-1477265161|page=137|url={{GBurl|id=3Z3a0NU4RHMC|p=137}}|access-date=4 August 2016|language=en|quote=He also conquered Sushen tribes in the northeast, Tungusic ancestors of the Jurcid and Manchus who later ruled Chinese "barbarian conquest dynasties" during the twelfth and seventeenth centuries.}}{{self-published source|date=December 2017}}</ref> and to the south, he defeated and subjugated [[Baekje]], contributed to the dissolution of [[Geumgwan Gaya|Gaya]], and vassalized [[Silla]] after defending it from a coalition of Baekje, Gaya, and Wa.<ref>{{cite book|last1=Lee|first1=Peter H.|last2=Ch'oe|first2=Yongho|last3=Kang|first3=Hugh H. W.|title=Sources of Korean Tradition: Volume One: From Early Times Through the Sixteenth Century|date= 1996|publisher=Columbia University Press|isbn=978-0231515313|pages=25–26|url={{GBurl|id=x9q69SroxWkC|p=25}}|access-date=21 October 2016|language=en}}</ref> Gwanggaeto brought about a loose unification of the Korean Peninsula,<ref name="Jinwung" /><ref>{{cite web|title=Kings and Queens of Korea|url=http://world.kbs.co.kr/english/archive/program/program_dynasty.htm?no=10039827|website=[[KBS World Radio]]|publisher=Korea Communications Commission|access-date=7 October 2016|archive-url=https://web.archive.org/web/20160828051916/http://world.kbs.co.kr/english/archive/program/program_dynasty.htm?no=10039827|archive-date=28 August 2016|url-status=dead}}</ref> and achieved undisputed control of most of [[Manchuria]] and over two thirds of the Korean Peninsula.<ref name="Jinwung" />

Gwanggaeto's exploits were recorded on a huge [[Gwanggaeto Stele|memorial stele]] erected by his son Jangsu, located in present-day [[Ji'an, Jilin|Ji'an]] on the border between China and North Korea.

[[Jangsu of Goguryeo|Jangsu]] (r. 413–491) ascended to the throne in 413 and moved the capital in 427 to [[Pyongyang]], a more suitable region to grow into a burgeoning metropolitan capital,<ref>{{cite book|last1=Lee|first1=Ki-Baik|title=A New History of Korea|date=1984|publisher=Harvard University Press|location=Cambridge, Massachusetts|isbn=978-0674615762|pages=38–40}} "This move from a region of narrow mountain valleys to a broad riverine plain indicates that the capital could no longer remain primarily a military encampment but had to be developed into a metropolitan center for the nation's political, economic, and social life."</ref> which led Goguryeo to achieve a high level of cultural and economic prosperity.<ref>{{cite book|last1=Kim|first1=Jinwung|title=A History of Korea: From "Land of the Morning Calm" to States in Conflict|publisher=Indiana University Press|isbn=978-0253000781|page=36|url={{GBurl|id=QFPsi3IK8gcC|p=36}}|access-date=15 July 2016|language=en|date=2012-11-05}} "Because Pyongyang was located in the vast, fertile Taedong River basin and had been the center of advanced culture of Old Chosŏn and Nangnang, this move led Koguryŏ to attain a high level of economic and cultural prosperity."</ref> Jangsu, like his father, continued Goguryeo's territorial expansion into Manchuria and reached the [[Songhua River]] to the north.<ref name="Jinwung" /> He invaded the Khitans, and then attacked the [[Didouyu]], located in eastern Mongolia, with his [[Rouran Khaganate|Rouran]] allies.<ref>{{cite book|script-title=ko:한나절에 읽는 백제의 역사|publisher=ebookspub(이북스펍)|isbn=979-1155191965|url={{GBurl|id=w8N3BgAAQBAJ|p=474}}|access-date=16 November 2016|language=ko|date=2014}}</ref> Like his father, Jangsu also achieved a loose unification of the [[Three Kingdoms of Korea]].<ref name="Jinwung" /> He defeated Baekje and Silla and gained large amounts of territory from both.<ref name="Lee" /><ref name="Jinwung" /> In addition, Jangsu's long reign saw the perfecting of Goguryeo's political, economic and other institutional arrangements.<ref name="Lee" /> Jangsu ruled Goguryeo for 79 years until the age of 98,<ref>{{cite book|last1=Lee|first1=Ki-Baik|title=A New History of Korea|date=1984|publisher=Harvard University Press|location=Cambridge, Massachusetts|isbn=978-0674615762|pages=38–40}}</ref> the longest reign in East Asian history.<ref>{{cite book|last1=Walker|first1=Hugh Dyson|title=East Asia: A New History|publisher=AuthorHouse|isbn=9781477265161|page=137|url={{GBurl|id=3Z3a0NU4RHMC|q=%22King+Changsu+succeeded+Kwanggaet%27o+and+ruled+Koguryo+for+79+years+%28412%E2%80%93491%29+the+longest+reign+in+East+Asian%2C+and+possibly%2C+world+history%21%22}}|access-date=29 July 2016|language=en|date=November 2012}}{{self-published source|date=December 2017}}</ref>{{Self-published inline|certain=yes|date=December 2017}}

During the reign of [[Munjamyeong of Goguryeo|Munja]], Goguryeo completely annexed Buyeo, signifying Goguryeo's furthest-ever expansion north, while continuing its strong influence over the kingdoms of Silla and Baekje, and the tribes of Wuji and Khitan.

===Internal strife (531 to 551)===
Goguryeo reached its zenith in the 6th century. After this, however, it began a steady decline. [[Anjang of Goguryeo|Anjang]] was assassinated, and succeeded by his brother [[Anwon of Goguryeo|Anwon]], during whose reign aristocratic factionalism increased. A political schism deepened as two factions advocated different princes for succession, until the eight-year-old Yang-won was finally crowned. But the power struggle was never resolved definitively, as renegade magistrates with private armies appointed themselves ''de facto'' rulers of their areas of control.

Taking advantage of Goguryeo's internal struggle, a nomadic group called the [[Göktürks|Tuchueh]] attacked Goguryeo's northern castles in the 550s and conquered some of Goguryeo's northern lands. Weakening Goguryeo even more, as civil war continued among feudal lords over royal succession, Baekje and Silla allied to attack Goguryeo from the south in 551.{{Citation needed|date=May 2019}}

===Conflicts of the late 6th and 7th centuries===
In the late 6th and early 7th centuries, Goguryeo was often in [[Military history of Goguryeo|military conflict]] with the Sui and Tang dynasties of China. Its relations with Baekje and Silla were complex and alternated between alliances and enmity. A neighbor in the northwest were the [[Eastern Turkic Khaganate|Eastern Türks]] which was a nominal ally of Goguryeo.

====Goguryeo's loss of the Han River Valley====
In 551 AD, [[Baekje]] and [[Silla]] entered into an alliance to attack Goguryeo and conquer the Han River valley, an important strategic area close to the center of the peninsula and a very rich agricultural region. After Baekje exhausted themselves with a series of costly assaults on Goguryeo fortifications, Silla troops, arriving on the pretense of offering assistance, attacked and took possession of the entire Han River valley in 553. Incensed by this betrayal, [[Seong of Baekje|Seong]] launched a retaliatory strike against Silla's western border in the following year but was captured and killed.

The war, along the middle of the [[Korean peninsula]], had very important consequences. It effectively made [[Baekje]] the weakest player on the [[Korean Peninsula]] and gave [[Silla]] an important resource and population rich area as a base for expansion. Conversely, it denied Goguryeo the use of the area, which weakened the kingdom. It also gave Silla direct access to the [[Yellow Sea]], opening up direct trade and diplomatic access to the Chinese dynasties and accelerating Silla's [[adoption of Chinese literary culture|adoption of Chinese culture]]. Thus, Silla could rely less on Goguryeo for elements of [[civilization]] and could get [[culture]] and [[technology]] directly from [[China]]. This increasing tilt of Silla to China would result in an alliance that would prove disastrous for Goguryeo in the late 7th century.

====Goguryeo–Sui War====
{{Main|Goguryeo–Sui War|Battle of Salsu}}

The [[Sui dynasty]]'s reunification of China for the first time in centuries was met with alarm in Goguryeo, and [[Pyeongwon of Goguryeo]] began preparations for a future war by augmenting military provisions and training more troops.<ref>{{cite web |script-title=ko:평원왕[平原王, ? – 590] |url=https://www.doopedia.co.kr/doopedia/master/master.do?_method=view&MAS_IDX=181755}}</ref> Although Sui was far larger and stronger than Goguryeo, the Baekje-Silla Alliance that had driven Goguryeo from the Han Valley had fallen apart, and thus Goguryeo's southern border was secure. Initially, Goguryeo tried to appease Sui by offering tribute as Korean kingdoms had done under the [[Tributary system of China]]. However, Goguryeo continued insistence on an equal relationship with Sui, its reinstatement of the imperial title "Taewang" (Emperor in Korean) of the East and its continued raids into Sui territory greatly angered the Sui Court. Furthermore, Silla and Baekje, both under threat from Goguryeo, requested Sui assistance against Goguryeo as all three Korean kingdoms had desired to seize the others' territories to rule the peninsula, and attempted to curry Sui's favor to achieve these goals.

Goguryeo's expansion and its attempts to equalize the relationship conflicted with [[Sui dynasty|Sui China]] and increased tensions. In 598, Goguryeo made a preemptive attack on [[Liaoxi Province|Liaoxi]] which led to the [[Battle of Linyuguan]], but was beaten back by Sui forces.<ref>{{cite book|last1=Yi|first1=Ki-baek|title=A New History of Korea|publisher=Harvard University Press|isbn=978-0674615762|page=47|url={{GBurl|id=g2mdVwXpMzwC|p=47}}|access-date=16 November 2016|language=en|year=1984}}</ref> This caused [[Emperor Wen of Sui|Emperor Wen]] to launch a counterattack by land and sea that ended in disaster for Sui.<ref name="White">{{cite book|last1=White|first1=Matthew|title=Atrocities: The 100 Deadliest Episodes in Human History|publisher=W. W. Norton & Company|isbn=978-0393081923|pages=78–79|url={{GBurl|id=0-fQHlaIpR4C|p=78}}|access-date=16 November 2016|language=en|date=2011-11-07}}</ref>

Sui's most disastrous campaign against Goguryeo was in 612, in which Sui, according to the History of the Sui dynasty, mobilized 30 division armies, about 1,133,800 combat troops. Pinned along Goguryeo's line of fortifications on the [[Liao River]], a detachment of nine division armies, about 305,000 troops, bypassed the main defensive lines and headed towards the Goguryeo capital of Pyongyang to link up with Sui naval forces, who had reinforcements and supplies.

However, Goguryeo was able to defeat the Sui navy, thus when the Sui's nine division armies finally reached Pyongyang, they didn't have the supplies for a lengthy siege. Sui troops retreated, but General [[Ŭlchi Mundŏk]] led the Goguryeo troops to victory by luring the Sui into an ambush outside of Pyongyang. At the [[Battle of Salsu]], Goguryeo soldiers released water from a dam, which split the Sui army and cut off their escape route. Of the original 305,000 soldiers of Sui's nine division armies, it is said that only 2,700 escaped to Sui China.

The 613 and 614 campaigns were aborted after launch—the 613 campaign was terminated when the Sui general [[Yang Xuangan]] rebelled against [[Emperor Yang of Sui|Emperor Yang]], while the 614 campaign was terminated after Goguryeo offered a truce and returned Husi Zheng (斛斯政), a defecting Sui general who had fled to Goguryeo, Emperor Yang later had Husi executed. Emperor Yang planned another attack on Goguryeo in 615, but due to Sui's deteroriating internal state he was never able to launch it. Sui was weakened due to rebellions against Emperor Yang's rule and his failed attempts to conquer Goguryeo. They could not attack further because the provinces in the Sui heartland would not send logistical support.

Emperor Yang's disastrous defeats in Korea greatly contributed to the collapse of the Sui dynasty.<ref name="White" /><ref>{{cite book|last1=Bedeski|first1=Robert|title=Human Security and the Chinese State: Historical Transformations and the Modern Quest for Sovereignty|publisher=Routledge|isbn=978-1134125975|page=90|url={{GBurl|id=iNl9AgAAQBAJ|p=90}}|access-date=16 November 2016|language=en|date=2007}}</ref><ref>{{cite book|last1=Ebrey|first1=Patricia Buckley|last2=Walthall|first2=Anne|last3=Palais|first3=James B.|title=East Asia: A Cultural, Social, and Political History, Volume I: To 1800|publisher=Cengage Learning|isbn=978-1111808150|page=106|url={{GBurl|id=CWE8AAAAQBAJ|p=106}}|access-date=16 November 2016|language=en|year=2013}}</ref>

====Goguryeo–Silla War, Goguryeo-Tang War and the Silla–Tang alliance====
{{Main|Goguryeo–Tang War|First campaign in the Goguryeo–Tang War|Siege of Ansi}}
[[Image:History of Korea-645.png|300px|thumb|right|First campaign in the Goguryeo–Tang War.]]

In the winter of 642, [[Yeongnyu of Goguryeo|King Yeongnyu]] was apprehensive about [[Yeon Gaesomun]], one of the great nobles of Goguryeo,<ref name="Medieval Chinese Warfare 300-900">{{cite book|last1=Graff|first1=David|title=Medieval Chinese Warfare 300–900|publisher=Routledge|isbn=978-1134553532|page=196|url={{GBurl|id=gpmBAgAAQBAJ|p=196}}|access-date=3 November 2016|language=en|date=2003}}</ref> and plotted with other officials to kill him. However, Yeon Gaesomun caught news of the plot and killed Yeongnyu and 100 officials, initiating a [[coup d'état]]. He proceeded to enthrone Yeongnyu's nephew, Go Jang, as [[Bojang of Goguryeo|King Bojang]] while wielding de facto control of Goguryeo himself as the Dae Magniji ({{Korean|hangul=대막리지|hanja=大莫離支|labels=no}}; a position equivalent to a modern era dual office of [[prime minister]] and [[generalissimo]]). At the outset of his rule, Yeon Gaesomun took a brief conciliatory stance toward Tang China. For instance, he supported [[Taoism in Korea|Taoism]] at the expense of [[Korean Buddhism|Buddhism]], and to this effect in 643, sent emissaries to the Tang court requesting Taoist sages, eight of whom were brought to Goguryeo. This gesture is considered by some historians as an effort to pacify Tang and buy time to prepare for the Tang invasion Yeon thought inevitable given his ambitions to annex Silla.

However, Yeon Gaesomun took an increasingly provocative stance against [[Silla|Silla Korea]] and [[Tang dynasty|Tang China]]. Soon, Goguryeo formed an alliance with Baekje and invaded Silla, Daeya-song (modern Hapchon) and around 40 border fortresses were conquered by the Goguryeo-Baekje alliance.<ref>{{cite web|last=Cartwright|first=Mark|title=Goguryeo|date=2016-10-05|url=https://www.worldhistory.org/Three_Kingdoms_Period_in_Korea|website=[[World History Encyclopedia]]}} Retrieved February 28, 2021</ref> Since the early 7th century, Silla had been forced on the defensive by both Baekje and Goguryeo, which had not yet formally allied but had both desired to erode Sillan power in the Han Valley. During the reign of King [[Jinpyeong of Silla]], numerous fortresses were lost to both Goguryeo and the continuous attacks took a toll on Silla and its people.<ref name="100.nate.com">{{cite web |script-title=ko:진평왕 |url=http://100.nate.com/dicsearch/pentry.html?s=K&i=271861&v=42 |website=[[Academy of Korean Studies]]| archive-url=https://web.archive.org/web/20110610011238/http://100.nate.com/dicsearch/pentry.html?s=K&i=271861&v=42 | archive-date=2011-06-10 }}</ref> During Jinpyeong's reign, Silla made repeated requests beseeching Sui China to attack Goguryeo.<ref name="100.nate.com"/> Although these invasions were ultimately unsuccessful, in 643, once again under pressure from the Goguryeo–Baekje alliance, Jinpyeong's successor, [[Queen Seondeok of Silla]], requested military aid from Tang. Although Taizong had initially dismissed Silla's offers to pay tribute and its requests for an alliance on account of Seondeok being a woman, he later accepted the offer due to Goguryeo's growing belligerence and hostile policy towards both Silla and Tang. In 644, Tang began preparations for a major campaign against Goguryeo.<ref name="Medieval Chinese Warfare 300-900"/>

In 645, [[Emperor Taizong of Tang|Emperor Taizong]], who had a personal ambition to defeat Goguryeo and was determined to succeed where [[Emperor Yang of Sui|Emperor Yang]] had failed, personally led an attack on Goguryeo. The Tang army captured a number of Goguryeo fortresses, including the important [[Yodong Fortress|Yodong/Liaodong Fortress]] (遼東城, in modern [[Liaoyang]], [[Liaoning]]). During his first campaign against Goguryeo, Taizong famously showed generously to the defeated inhabitants of numerous Goguryeo fortresses, refusing to permit his troops to loot downs and enslave inhabitants and when faced with protest from his commanders and soldiers, rewarded them with his own money.<ref name="Medieval Chinese Warfare 300–900">{{cite book |last1=Graff |first1=David |title=Medieval Chinese Warfare 300–900 |date=2001 |publisher=Routledge |page=197}}</ref> [[Ansi City]] (in modern [[Haicheng, Liaoning|Haicheng]], Liaoning), which was the last fortress that would clear the [[Liaodong Peninsula]] of significant defensive works and was promptly put under siege. Initially, Taizong and his forces achieve great progress, when his numerically inferior force smashed a Goguryeo relief force at the [[Battle of Mount Jupil]]. Goguryeo's defeat at Mount Jupil had significant consequences, as Tang forces killed over 20,000 Goguryeo soldiers and captured another 36,800, which crippled Goguryeo's manpower reserves for the rest of the conflict.<ref name="Medieval Chinese Warfare 300–900"/> However, the capable defense put up by Ansi's commanding general (whose name is controversial but traditionally is believed to be [[Yang Manchun]]) stymied Tang forces and, in late fall, with winter fast approaching and his supplies running low, Tang forces under the command Prince Li Daozong attempted to build a rampart to seize the city in a last ditch effort, but was foiled when Goguryeo troops managed to seize control of it. Afterwards, Taizong decided to withdraw in the face of incoming Goguryeo reinforcements, deteriorating weather conditions and the difficult supply situation. The campaign was unsuccessful for the Tang Chinese,<ref name="World History P464"/> failing to capture Ansi Fortress after a protracted siege that lasted more than 60 days.<ref>{{cite book|last1=Yi|first1=Ki-baek|title=A New History of Korea|publisher=Harvard University Press|isbn=978-0674615762|page=48|url={{GBurl|id=g2mdVwXpMzwC|p=48}}|access-date=2 November 2016|language=en|year=1984}}</ref> Emperor Taizong invaded Goguryeo again in 647 and 648, but was defeated both times.<ref name="Kim">{{cite book|last1=Kim|first1=Jinwung|title=A History of Korea: From "Land of the Morning Calm" to States in Conflict|publisher=Indiana University Press|isbn=978-0253000781|page=50|url={{GBurl|id=QFPsi3IK8gcC|q=%22In+647+and+648+Taizong+again+dispatched+expeditionary+forces+to+invade+Kogury%C5%8F%2C+but+these+attacks%2C+too%2C+were+repulsed+by+Kogury%C5%8F.+Taizong+never+accomplished+his+ambition+to+conquer+Kogury%C5%8F+in+his+lifetime.%22}}|access-date=2 August 2016|language=en|date=2012}}</ref><ref>{{cite book|last1=Ebrey|first1=Patricia Buckley|last2=Walthall|first2=Anne|last3=Palais|first3=James B.|title=East Asia: A Cultural, Social, and Political History, Volume I: To 1800|publisher=Cengage Learning|isbn=978-1111808150|page=106|url={{GBurl|id=CWE8AAAAQBAJ|q=%22Still+convinced+that+he+could+defeat+Koguryo%2C+Taizong+dispatched+two+more+expeditions+against+it+in+647+and+648%2C+neither+of+them+successful.%22}}|access-date=4 August 2016|language=en|year=2013}}</ref><ref>{{cite book|last1=Tucker|first1=Spencer C.|title=A Global Chronology of Conflict: From the Ancient World to the Modern Middle East [6 volumes]: From the Ancient World to the Modern Middle East|publisher=ABC-CLIO|isbn=978-1851096725|page=406|url={{GBurl|id=h5_tSnygvbIC|q=%22In+645+he+led+Tang+forces+to+conquer+Koguryo+but+was+defeated.+Again+in+647+and+648+he+sent+out+expeditionary+forces+to+invade+Koguryo%2C+but+these+attacks+were+also+repulsed+by+the+Korean+kingdom.%22}}|access-date=4 August 2016|language=en|date=2009}}</ref><ref name="Wei">{{cite book|last1=Chen|first1=Jack Wei|title=The Poetics of Sovereignty: On Emperor Taizong of the Tang Dynasty|publisher=Harvard University Press|isbn=978-0674056084|page=43|url={{GBurl|id=5wlDivOQGakC|p=43}}|access-date=4 August 2016|language=en|year=2010}}</ref><ref>{{cite book|last1=Guo|first1=Rongxing|title=Intercultural Economic Analysis: Theory and Method|publisher=Springer Science & Business Media|isbn=978-1441908490|page=42|url={{GBurl|id=dbJ3LsL6jJMC|q=%22The+subsequent+dynasty%2C+Tang+%28AD+618%E2%80%93907%29%2C+dispatched+three+unsuccessful+expeditions+against+Koguryo+in+AD+644%2C+648%2C+and+655.%22}}|access-date=4 August 2016|language=en|date=2009}}</ref>

[[File:Korean ambassadors to the Tang court, 7th century CE.jpg|thumb|Painting of envoys from the Three Kingdoms of Korea to the [[Tang dynasty|Tang]] court: Silla, Baekje, and Goguryeo. ''[[Portraits of Periodical Offering]]'', circa 650 AD, Tang dynasty]]
[[File:Korean ambassadors during a audience with king Varkhuman of Samarkand. 648-651 CE, Afrasiyab, Samarkand.jpg|upright=0.8|thumb|Goguryeo ambassadors during an audience with King [[Varkhuman]] of [[Samarkand]]. They are identified by the two feathers on top of their head.<ref>{{cite book |last1=Library |first1=British |title=The Silk Road: Trade, Travel, War and Faith |year=2004 |publisher=Serindia Publications, Inc. |isbn=978-1-932476-13-2 |page=110 |url={{GBurl|id=ArWLD4Qop38C|p=110}} |language=en}}</ref> 648–651 AD, [[Afrasiab murals]], Samarkand.<ref>{{cite book |last1=Baumer |first1=Christoph |title=History of Central Asia, The: 4-volume set |date=18 April 2018 |publisher=Bloomsbury Publishing |isbn=978-1-83860-868-2 |page=243 |url={{GBurl|id=DhiWDwAAQBAJ|pg=RA1-PA243}} |language=en}}</ref><ref>{{cite journal |last1=Grenet |first1=Frantz |title=Maracanda/Samarkand, une métropole pré-mongole |journal=Annales. Histoire, Sciences Sociales |date=2004 |volume=5/6 |page=Fig. C |url=https://www.cairn.info/journal-annales-2004-5-page-1043.htm}}</ref>]]
Emperor Taizong prepared another invasion in 649, but died in the summer, possibly due to an illness he contracted during his Korean campaigns.<ref name="Wei" /><ref name="Kim" /> His son [[Emperor Gaozong of Tang|Emperor Gaozong]] continued his campaigns. Upon the suggestion of [[Muyeol of Silla|Kim Chunchu]], the Silla–Tang alliance first conquered [[Baekje]] in 660 to break up the Goguryeo–Baekje alliance, and then turned its full attention to Goguryeo.<ref name="oceania">{{cite book|last1=Ring|first1=Trudy|last2=Watson|first2=Noelle|last3=Schellinger|first3=Paul|title=Asia and Oceania: International Dictionary of Historic Places|publisher=Routledge|isbn=978-1136639791|page=486|url={{GBurl|id=voerPYsAB5wC|q=stalwart+defenses}}|access-date=16 July 2016|language=en|date=2012}}</ref> However, Emperor Gaozong, too, was unable to defeat Goguryeo led by [[Yeon Gaesomun]];<ref name="oceania" /><ref name="maps">{{cite book|last1=Injae|first1=Lee|last2=Miller|first2=Owen|last3=Jinhoon|first3=Park|last4=Hyun-Hae|first4=Yi|title=Korean History in Maps|publisher=Cambridge University Press|isbn=978-1107098466|page=29|url={{GBurl|id=46OTBQAAQBAJ|p=29}}|access-date=4 August 2016|language=en|date=2014}}</ref> one of Yeon Gaesomun's most notable victories came in 662 at the ''Battle of Sasu'' (蛇水), where he annihilated the Tang forces and killed the invading ex-rebel [[Nanman]] general Pang Xiaotai (龐孝泰) and all 13 of his sons.<ref>{{cite book|last1=이희진|date=2013|script-title=ko:옆으로 읽는 동아시아 삼국지 1|publisher=EastAsia |isbn=978-8962620726|url={{GBurl|id=GfevAwAAQBAJ|pg=PT348}}|access-date=4 November 2016|language=ko}}</ref><ref>{{cite web|script-title=ko:통일기|url=http://www.culturecontent.com/content/contentView.do?search_div_id=CP_THE003&cp_code=cp0901&index_id=cp09010004&content_id=cp090100040001&search_left_menu=1|website=한국콘텐츠진흥원|publisher=Korea Creative Content Agency|access-date=4 November 2016}}</ref> Therefore, while Yeon Gaesomun was alive, Tang could not defeat Goguryeo.<ref>{{cite book|last1=김용만|year=1998|script-title=ko:고구려의발견: 새로쓰는고구려문명사|publisher=바다출판사|isbn=978-8987180212|page=486|url={{GBurl|id=0iN1PAAACAAJ|q=%EA%B3%A0%EA%B5%AC%EB%A0%A4%EC%9D%98+%EB%B0%9C%EA%B2%AC}}|access-date=4 November 2016|language=ko}}</ref>

====Fall====
In the summer of 666, [[Yeon Gaesomun]] died of a natural cause and Goguryeo was thrown into chaos and weakened by a succession struggle among his sons and younger brother.<ref name="Succession">{{cite book|last1=Yi|first1=Ki-baek|title=A New History of Korea|year=1984|publisher=Harvard University Press|isbn=978-0674615762|page=67|url={{GBurl|id=g2mdVwXpMzwC|p=67}}|access-date=2 August 2016|language=en}}</ref> He was initially succeeded as ''Dae Mangniji'', the highest position newly made under the ruling period of Yeon Gaesomun, by his oldest son [[Yeon Namsaeng]]. As Yeon Namsaeng subsequently carried out a tour of Goguryeo territory, however, rumors began to spread both that Yeon Namsaeng was going to kill his younger brothers [[Yeon Namgeon]] and [[Yeon Namsan]], whom he had left in charge at [[Pyongyang]], and that Yeon Namgeon and Yeon Namsan were planning to rebel against Yeon Namsaeng. When Yeon Namsaeng subsequently sent officials close to him back to Pyongyang to try to spy on the situation, Yeon Namgeon arrested them and declared himself ''Dae Mangniji'', attacking his brother. Yeon Namsaeng sent his son [[Gwon Saseong|Cheon Heonseong]] (泉獻誠), as Yeon Namsaeng changed his family name from Yeon (淵) to Cheon (泉) observe naming taboo for Emperor Gaozu, to Tang to seek aid. [[Emperor Gaozong of Tang|Emperor Gaozong]] saw this as an opportunity and sent an army to attack and destroy Goguryeo. In the middle of Goguryeo's power struggles between Yeon Gaesomun's successors, his younger brother, Yeon Jeongto, defected to the Silla side.<ref name="Succession" />

In 667, the Chinese army crossed the [[Liao River]] and captured Shin/Xin Fortress (新城, in modern [[Fushun]], [[Liaoning]]). The Tang forces thereafter fought off counterattacks by Yeon Namgeon, and joined forces with and received every possible assistance from the defector Yeon Namsaeng,<ref name="Succession" /> although they were initially unable to cross the Yalu River due to resistance. In spring of 668, Li Ji turned his attention to Goguryeo's northern cities, capturing the important city of Buyeo (扶餘, in modern [[Nong'an County|Nong'an]], [[Jilin]]). In fall of 668, he crossed the [[Yalu River]] and put [[Pyongyang]] under siege in concert with the Silla army.

Yeon Namsan and Bojang surrendered, and while Yeon Namgeon continued to resist in the inner city, his general, the Buddhist monk [[Shin Seong]] (信誠) turned against him and surrendered the inner city to Tang forces. Yeon Namgeon tried to commit suicide, but was seized and treated. This was the end of Goguryeo, and Tang annexed Goguryeo into its territory, with [[Xue Rengui]] being put initially in charge of former Goguryeo territory as protector general. The violent dissension resulting from Yeon Gaesomun's death proved to be the primary reason for the Tang–Silla triumph, thanks to the division, defections, and widespread demoralization it caused.<ref name="Graff200">{{cite book|last1=Graff|first1=David|title=Medieval Chinese Warfare 300–900|date=2003|publisher=Routledge|isbn=978-1134553532|page=200|url={{GBurl|id=gpmBAgAAQBAJ|p=200}}|access-date=6 November 2016|language=en}}</ref> The alliance with Silla had also proved to be invaluable, thanks to the ability to attack Goguryeo from opposite directions, and both military and logistical aid from Silla.<ref name="Graff200" /> The Tang established the [[Andong Protectorate]] on former Goguryeo lands after the latter's fall.{{sfn|Wang|2013|p=81}}{{sfn|Xiong|2008|p=43}}

However, there was much resistance to Tang rule (fanned by Silla, which was displeased that Tang did not give it Goguryeo or Baekje's territory), and in 669, following Emperor Gaozong's order, a part of the Goguryeo people were forced to move to the region between the Yangtze River and the Huai River, as well as the regions south of the Qinling Mountains and west of Chang'an, only leaving old and weak inhabitants in the original land. Over 200,000 prisoners from Goguryeo were taken by the Tang forces and sent to [[Chang'an]].<ref>{{cite book | last=Lewis | first=Mark Edward | title=China's cosmopolitan empire: The Tang dynasty | year=2009 | publisher=Harvard University Press | location=Cambridge | isbn=9780674033061}}</ref> Some people entered the service of the Tang government, such as [[Go Sagye]] and his son [[Gao Xianzhi]] (Go Seonji in Korean), the famed general who commanded the Tang forces at the [[Battle of Talas]].<ref>{{cite book|last1=Graff|first1=David|title=Medieval Chinese Warfare 300–900|date=2003|publisher=Routledge|isbn=978-1134553532|page=213|url={{GBurl|id=gpmBAgAAQBAJ|p=213}}|access-date=29 July 2016|language=en}}</ref><ref>{{cite book|last1=Grant|first1=Reg G.|title=1001 Battles That Changed the Course of World History|year=2011|publisher=Universe Pub.|isbn=978-0789322333|page=118|url={{GBurl|id=s4njwZGrZg4C|p=118}}|access-date=29 July 2016|language=en}}</ref><ref>{{cite book|last1=Starr|first1=S. Frederick|title=Xinjiang: China's Muslim Borderland|date=2015|publisher=Routledge|isbn=978-1317451372|page=38|url={{GBurl|id=XuvqBgAAQBAJ|p=38}}|access-date=29 July 2016|language=en}}</ref><ref>{{cite book|last1=Connolly|first1=Peter|last2=Gillingham|first2=John|last3=Lazenby|first3=John|title=The Hutchinson Dictionary of Ancient and Medieval Warfare|date=
2016|publisher=Routledge|isbn=978-1135936815|url={{GBurl|id=1LUoDAAAQBAJ|pg=PT263}}|access-date=29 July 2016|language=en}}</ref><ref>{{cite book|last1=Neelis|first1=Jason|title=Early Buddhist Transmission and Trade Networks: Mobility and Exchange Within and Beyond the Northwestern Borderlands of South Asia|date=2010|publisher=Brill|isbn=978-9004181595|page=176|url={{GBurl|id=GB-JV2eOr2UC|p=176}}|access-date=29 July 2016|language=en}}</ref>

Silla thus unified most of the Korean peninsula in 668, but the kingdom's reliance on China's Tang dynasty had its price. Tang set up the [[Protectorate General to Pacify the East]], governed by [[Xue Rengui]], but faced increasing problems ruling the former inhabitants of Goguryeo, as well as Silla's resistance to Tang's remaining presence on the Korean Peninsula. Silla had to forcibly resist the imposition of Chinese rule over the entire peninsula, which lead to the [[Silla–Tang War]]s, but their own strength did not extend beyond the [[Taedong River]].{{citation needed|date=January 2018}} Although the Tang forces were expelled from territories south of Taedong River, Silla failed to regain the former Goguryeo territories north of the [[Taedong River]], which were now under Tang dominion.<ref name=fuqua07-40>{{cite book | last=Fuqua|first=Jacques L. | title=Nuclear endgame: The need for engagement with North Korea|year=2007|publisher=Praeger Security International|location=Westport|isbn=9780275990749 | page=40}}</ref>

====Revival movements====
{{Main|Goguryeo revival movements}}
{{See also|Balhae}}

After the fall of Goguryeo in 668, many Goguryeo people rebelled against the Tang and Silla by starting Goguryeo revival movements. Among these were [[Geom Mojam]], [[Dae Jung-sang]], and several famous generals. The Tang dynasty tried but failed to establish several commanderies to rule over the area.

In 677, Tang crowned [[Bojang of Goguryeo|Bojang]] as the "King of [[Names of Korea#Joseon|Joseon]]" and put him in charge of the Liaodong commandery of the [[Protectorate General to Pacify the East]]. However, Bojang continued to foment rebellions against Tang in an attempt to revive Goguryeo, organizing Goguryeo refugees and allying with the Mohe tribes. He was eventually exiled to [[Sichuan]] in 681, and died the following year.

The [[Protectorate General to Pacify the East]] was installed by the Tang government to rule and keep control over the former territories of the fallen Goguryeo. It was first put under the control of Tang General [[Xue Rengui]], but was later replaced by Bojang due to the negative responses of the Goguryeo people. Bojang was sent into exile for assisting Goguryeo revival movements, but was succeeded by his descendants. Bojang's descendants declared independence from [[Tang dynasty|Tang]] during the same period as the [[An Lushan Rebellion]] and [[Li Zhengji]] (Yi Jeong-gi in Korean)'s rebellion in [[Shandong]].<ref>《資治通鑑·唐紀四十一》</ref><ref>《資治通鑑·唐紀四十三》</ref> The Protectorate General to Pacify the East was renamed "[[Little Goguryeo]]" until its eventual absorption into Balhae under the reign of [[Seon of Balhae|Seon]].

[[Geom Mojam]] and [[Anseung]] rose briefly at the Han Fortress (한성, 漢城, in modern [[Chaeryong County|Chaeryong]], [[South Hwanghae Province|South Hwanghae]]), but failed, when Anseung surrendered to [[Silla]]. Go Anseung ordered the assassination of Geom Mojam, and defected to Silla, where he was given a small amount of land to rule over. There, Anseung established the [[Bodeok|State of Bodeok]] ({{Korean|hangul=보덕|hanja=報德|labels=no}}), incited a rebellion, which was promptly crushed by [[Sinmun of Silla|Sinmun]]. Anseung was then forced to reside in the Silla capital, given a Silla bride and had to adopt the Silla royal surname of "Kim."

[[Dae Jung-sang]] and his son [[Go of Balhae|Dae Jo-yeong]], either a former Goguryeo general or a [[Mohe people|Mohe]] chief, regained most of Goguryeo's northern land after its downfall in 668, established the [[Balhae|Kingdom of Jin]] ({{Korean|hangul=진|hanja=震|labels=no}}), which was renamed to [[Balhae]] after 713. To the south of [[Balhae]], [[Silla]] controlled the Korean peninsula south of the [[Taedong River]], and [[Manchuria]] (now [[Northeast China|northeastern China]]) was conquered by Balhae. Balhae considered itself (particularly in diplomatic correspondence with Japan) a [[Succession of states|successor state]] of Goguryeo.

In 901, the general [[Gung Ye]] rebelled against [[Later Silla]] and founded Later Goguryeo (renamed to [[Taebong]] in 911), which considered itself to be a successor of Goguryeo. Later Goguryeo originated in the northern regions, including [[Kaesong|Songak]] (modern Kaesong), which were the strongholds of Goguryeo refugees.<ref>{{cite book|last1=이상각|script-title=ko:고려사 – 열정과 자존의 오백년|date=2014|publisher=들녘|isbn=979-1159250248|url={{GBurl|id=LonnCgAAQBAJ|pg=PT25}}|access-date=23 March 2018|language=ko}}</ref><ref>{{cite web|title=(2) 건국―호족들과의 제휴|url=http://contents.history.go.kr/front/nh/view.do?levelId=nh_011_0040_0030_0020_0020|website=우리역사넷|publisher=[[National Institute of Korean History]]|access-date=23 March 2018|language=ko}}</ref> Later Goguryeo's original capital was established in Songak, the hometown of [[Taejo of Goryeo|Wang Geon]], a prominent general under Gung Ye.<ref>{{cite book|last1=성기환|script-title=ko:생각하는 한국사 2: 고려시대부터 조선·일제강점까지|date=2008|publisher=버들미디어|isbn=978-8986982923|url={{GBurl|id=gQ3-AwAAQBAJ|pg=PT6}}|access-date=23 March 2018|language=ko}}</ref> Wang Geon was a descendant of Goguryeo and traced his ancestry to a noble Goguryeo clan.<ref>{{cite book|last1=박|first1=종기|date= 2015|script-title=ko:고려사의 재발견: 한반도 역사상 가장 개방적이고 역동적인 500년 고려 역사를 만나다|publisher=휴머니스트|isbn=978-8958629023|url={{GBurl|id=Qn6TCgAAQBAJ|pg=PT59}}|access-date=27 October 2016|language=ko}}</ref> In 918, Wang Geon overthrew Gung Ye and established [[Goryeo]], as the successor of Goguryeo, and laid claim to Manchuria as Goryeo's rightful legacy.<ref name="Goryeo">{{cite book|last1=Yi|first1=Ki-baek|title=A New History of Korea|year=1984|publisher=Harvard University Press|isbn=978-0674615762|page=103|url={{GBurl|id=g2mdVwXpMzwC|p=103}}|access-date=20 October 2016|language=en}}</ref><ref name="Rossabi">{{cite book|last1=Rossabi|first1=Morris|title=China Among Equals: The Middle Kingdom and Its Neighbors, 10th–14th Centuries|date=1983|publisher=University of California Press|isbn=978-0520045620|page=323|url={{GBurl|id=sNpD5UKmkswC|q=%22As+the+self-proclaimed+successor+to+Koguryo+and+the+protector+of+Parhae+refugees%2C+many+of+them+of+Koguryo+origin%2C+Koryo+considered+the+northern+territories+in+Manchuria+its+rightful+legacy.%22}}|access-date=1 August 2016|language=en}}</ref><ref name="seohui">{{cite book|last1=Kim|first1=Djun Kil|title=The History of Korea|date=2005|publisher=ABC-CLIO|isbn=978-0313038532|page=57|url={{GBurl|id=ci_iGuAAqmsC|p=57}}|access-date=20 October 2016|language=en}}</ref><ref name="Grayson">{{cite book|last1=Grayson|first1=James H.|title=Korea – A Religious History|date=2013|publisher=Routledge|isbn=978-1136869259|page=79|url={{GBurl|id=LU78AQAAQBAJ|p=79}}|access-date=20 October 2016|language=en}}</ref> Wang Geon unified the [[Later Three Kingdoms]] in 936, and Goryeo ruled the Korean Peninsula until 1392.

In the 10th century, Balhae collapsed and much of its ruling class and the last crown prince [[Dae Gwang-hyeon]] fled to Goryeo. The Balhae refugees were warmly welcomed and included in the ruling family by Wang Geon, who felt a strong familial kinship with Balhae,<ref name="Rossabi" /><ref>{{cite book|last1=박종기|script-title=ko:고려사의 재발견: 한반도 역사상 가장 개방적이고 역동적인 500년 고려 역사를 만나다|date=2015|publisher=휴머니스트|isbn=978-8958629023|url={{GBurl|id=Qn6TCgAAQBAJ|pg=PT66}}|access-date=23 March 2018|language=ko}}</ref><ref>{{cite web|last1=박용운|script-title=ko:'고구려'와 '고려'는 같은 나라였다|url=http://www.chosun.com/culture/news/200606/200606160471.html|website=조선닷컴|publisher=[[The Chosun Ilbo]]|access-date=23 March 2018|archive-url=https://web.archive.org/web/20170622072057/http://www.chosun.com/culture/news/200606/200606160471.html|archive-date=22 June 2017|url-status=dead|df=dmy-all}}</ref> thus unifying the two successor nations of Goguryeo.<ref>{{cite book|last1=Lee|first1=Ki-Baik|title=A New History of Korea|date=1984|publisher=Harvard University Press|location=Cambridge, Massachusetts|isbn=978-0674615762|page=103}} "When Parhae perished at the hands of the Khitan around this same time, much of its ruling class, who were of Koguryŏ descent, fled to Koryŏ. Wang Kŏn warmly welcomed them and generously gave them land. Along with bestowing the name Wang Kye ("Successor of the Royal Wang") on the Parhae crown prince, Tae Kwang-hyŏn, Wang Kŏn entered his name in the royal household register, thus clearly conveying the idea that they belonged to the same lineage, and also had rituals performed in honor of his progenitor. Thus Koryŏ achieved a true national unification that embraced not only the Later Three Kingdoms but even survivors of Koguryŏ lineage from the Parhae kingdom."</ref>