Editing Goguryeo (section)

===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>