Editing Sejong the Great (section)

===Military===
King Sejong was an effective military planner and created various military regulations to strengthen the safety of his kingdom.<ref name=":0">{{Cite book |last=Park |first=Young-gyu |script-title=ko:한권으로 읽는 세종대왕실록 |publisher=Woongjin Knowledge House |isbn=9788901077543 |publication-date=12 February 2008 |language=Korean |trans-title=Veritable Records of King Sejong the Great in One Volume}}</ref>{{Place missing|date=July 2024}} During his reign great technological advancements were made in the manufacture of [[gunpowder]] and [[firearm]]s. Hand cannons, known as ''Wangu'' ({{Korean|hangul=완구|hanja=碗口|labels=no}}), first built in 1407 and 1418, were improved upon,<ref>{{Citation |last=이 |first=강칠 |script-title=ko:완구 (碗口) |encyclopedia=[[Encyclopedia of Korean Culture]] |url=https://encykorea.aks.ac.kr/Article/E0038953 |access-date=2024-08-15 |publisher=[[Academy of Korean Studies]] |language=ko}}</ref> and the ''Sohwapo'' ({{Korean|hangul=소화포|hanja=小火砲|labels=no}}), ''Cheoljetanhwan'' ({{Korean|hangul=철제탄환|labels=no}}), ''Hwapojeon'' ({{Korean|hangul=화포전|hanja=火砲箭|labels=no}}) and the ''Hwacho'' ({{Korean|hangul=화초|hanja=火硝|labels=no}}) were invented during his reign.<ref name=":1">{{Citation |last=최 |first=승희 |script-title=ko:세종 (世宗) |encyclopedia=[[Encyclopedia of Korean Culture]] |url=https://encykorea.aks.ac.kr/Article/E0029857#section-7 |access-date=2024-08-15 |publisher=[[Academy of Korean Studies]] |language=ko}}</ref>

None of these had yet reached a satisfactory level for Sejong. In the 26th year of his reign, he had the cannon foundry ''Hwapojujoso'' ({{Korean|hangul=화포주조소|hanja=火砲鑄造所|labels=no}}) built to produce a new [[Standardization|standard]] cannon with outstanding performance, and in the following year, he undertook a complete overhaul of the cannon. The ''Chongtongdeungnok'' ({{Korean|hangul=총통등록|hanja=銃筒謄錄|labels=no}}) compiled and published in the 30th year his reign, was an illustrated book that described the [[Casting|casting methods]], gunpowder usage, and specifications of the guns. The publication of this book is considered a remarkable achievement that marked a new era in the manufacture of artillery during the Joseon Dynasty.<ref name=":1" />

In June 1419, under his father's counsel, Sejong ordered the third and last military campaign of [[Tsushima Island|Tsushima]]. This incident is known as the ''Gihae Expedition'' in Korean and ''[[Ōei Invasion]]'' in Japanese. The military expedition was aimed at eradicating the taproot of the Japanese pirates' pillaging the southern villages of the Joseon dynasty. During the invasion, 245 Japanese were executed or killed and another 110 were captured, while 180 Korean soldiers died. Around 150 who had been kidnapped (146 Chinese and 8 Koreans) were also freed.<ref>{{Citation |script-title=ko:대마도 정벌 (對馬島 征伐) |encyclopedia=[[Encyclopedia of Korean Culture]] |url=https://encykorea.aks.ac.kr/Article/E0014343 |access-date=2024-08-15 |publisher=[[Academy of Korean Studies]] |language=ko}}</ref> A truce was made in July 1419, and the Joseon army returned to the Korean Peninsula, but no official documents were signed until 1443. In this agreement, known as the [[Treaty of Gyehae]], the ''[[daimyo]]'' of Tsushima was obliged to pay tribute to the Joseon monarch, and in return, the [[Sō clan]] was allowed to serve as a diplomatic intermediary between Korea and Japan, as well as retain exclusive trade rights.{{Efn|500 years later, the 39th head of the [[Sō clan]], [[Count]] [[Sō Takeyuki]], married [[Princess Deokhye]], youngest daughter of [[Gojong of Korea|Emperor Gojong]] and half-sister of [[Sunjong of Korea|Sunjong]], the last [[Korean Empire|Emperor of Korea]].}}<ref>{{cite web |script-title=ko:계해약조 |trans-title=Treaty of Gyehae |url=http://preview.britannica.co.kr/bol/topic.asp?article_id=b01g3496a |url-status=unfit |archive-url=https://web.archive.org/web/20090114065908/http://preview.britannica.co.kr/bol/topic.asp?article_id=b01g3496a |archive-date=14 January 2009 |access-date=25 October 2008 |website=[[Encyclopædia Britannica]] |language=Korean}}</ref>

In 1433, Sejong sent [[Kim Chongsŏ]] to the north to conquer the [[Jurchen people|Jurchens]]. The military campaign captured several fortresses and expanded the Korean territory northward up to the [[Songhua River]].<ref>{{cite web |script-title=ko:21세기 세종대왕 프로젝트 |trans-title=21st-century King Sejong the Great project |url=http://sejong.prkorea.com/kor/letter/letter.jsp |access-date=22 February 2016 |website=sejong.prkorea.com |language=Korean}}</ref><ref name=":0" />{{Place missing|date=July 2024}}