# Nam I and Gang Sun's plot
**Nam I and Gang Sun's plot** (남이·강순의 옥사) was a treason case of 1468 in which the Joseon generals [Nam I](https://www.edgepedia.org/nam-i) (남이) and Gang Sun (강순) were accused, on fabricated charges brought by the official Yu Ja-gwang, and Nam I was executed after interrogation by lingchi (neungji cheosa, dismemberment).[1](https://encykorea.aks.ac.kr/Article/E0012096) • [2](https://yongin.grandculture.net/yongin/toc/GC00900697) The veteran ministers around [Sin Suk-ju](https://www.edgepedia.org/sin-suk-ju) and [Han Myeong-hoe](https://www.edgepedia.org/han-myeong-hoe) moved against the young commanders who had risen by suppressing Yi Si-ae's rebellion in 1467.[2](https://yongin.grandculture.net/yongin/toc/GC00900697) • [3](http://www.e-sejong.co.kr/news/articleView.html?idxno=10354)
| Item | Detail |
|---|---|
| Date | 1468, in the first months of Yejong's reign[1](https://encykorea.aks.ac.kr/Article/E0012096) • [2](https://yongin.grandculture.net/yongin/toc/GC00900697) |
| Accused | Nam I, Minister of Military Affairs and former first-grade Jeokgae merit subject; Gang Sun, chief commander of the 1467 campaigns[1](https://encykorea.aks.ac.kr/Article/E0012096) • [4](https://www.m-joongang.com/news/articleView.html?idxno=400786) |
| Accusers | Yu Ja-gwang (Byeongjo chamji), backed by the old ministers Sin Suk-ju and Han Myeong-hoe[1](https://encykorea.aks.ac.kr/Article/E0012096) • [2](https://yongin.grandculture.net/yongin/toc/GC00900697) |
| Outcome | Nam I executed by lingchi[1](https://encykorea.aks.ac.kr/Article/E0012096) • [2](https://yongin.grandculture.net/yongin/toc/GC00900697) |
| Aftermath | Posthumous rehabilitation of Nam I and Gang Sun in 1818[5](http://www.grandculture.net/hwaseong/toc/GC08600609) • [6](https://www.joongang.co.kr/article/25447689) |
## Background and causes
Nam I passed the military examination, held posts under King Sejo's favor, and in 1467 became a general (udaejang) in the army sent against [Yi Si-ae](https://www.edgepedia.org/yi-si-ae)'s rebellion in the northern Hamgil region. For this suppression Nam I was enrolled as a first-grade Jeokgae merit subject and enfeoffed as Uisan-gun.[1](https://encykorea.aks.ac.kr/Article/E0012096) • [2](https://yongin.grandculture.net/yongin/toc/GC00900697)
In the campaign against the [Jianzhou Jurchens](https://www.edgepedia.org/jianzhou-jurchens), Gang Sun was main commander, Nam I right-division grand general, and Eo Yu-so left-division grand general. On 26 September Gang Sun and Nam I attacked from Manpo into the Paje River, beheading the chieftain [Li Manzhu](https://www.edgepedia.org/li-manzhu).[4](https://www.m-joongang.com/news/articleView.html?idxno=400786) • [1](https://encykorea.aks.ac.kr/Article/E0012096) Nam I received second-grade military merit and was appointed Minister of Works, then in 1468 concurrently Do-chonggwan of the [Five Military Commands](https://www.edgepedia.org/five-military-commands) and Minister of Military Affairs (Byeongjo panseo).[2](https://yongin.grandculture.net/yongin/toc/GC00900697) • [5](http://www.grandculture.net/hwaseong/toc/GC08600609)
The cause of the case was the conflict between the established ministers and the new men. The 45 merit subjects of the rebellion's suppression, including [Yi Jun](https://www.edgepedia.org/yi-jun), Nam I, and Yu Ja-gwang, served to check the older merit subjects Han Myeong-hoe and Sin Suk-ju, and this conflict later surfaced in the Guiseong-gun affair and in Nam I's case.[7](https://contents.history.go.kr/mobile/kc/view.do?code=kc_age_30&levelId=kc_i305100) After Yejong's accession, the old-guard faction around Sin Suk-ju and Han Myeong-hoe moved to remove the new men.
## Course of events
1. **October 1468.** While on night duty in the palace, Nam I remarked on the appearance of a comet that it was an omen of removing the old and bringing in the new. Yu Ja-gwang, then Deputy Minister of Military Affairs (Byeongjo chamji), who overheard this, accused him of plotting treason.[1](https://encykorea.aks.ac.kr/Article/E0012096) • [2](https://yongin.grandculture.net/yongin/toc/GC00900697)
2. **After interrogation.** Nam I was executed by lingchi (neungji cheosa).[1](https://encykorea.aks.ac.kr/Article/E0012096) • [2](https://yongin.grandculture.net/yongin/toc/GC00900697)
Gang Sun, the main commander of the 1467 campaigns, was also caught up in the purge of the new military leaders; his offices, like Nam I's, were posthumously restored in 1818 as those of a man who had perished through Yu Ja-gwang's false accusation.[2](https://yongin.grandculture.net/yongin/toc/GC00900697) • [6](https://www.joongang.co.kr/article/25447689)
A further element in the tradition is the poem. One account states that Yu Ja-gwang altered the third line of Nam I's verse, changing the character for "pacify" (平) in mipyeongguk (未平國, "a not-yet-pacified state") to "obtain" (得), so that a line about a man of twenty who had not pacified the troubled state became a line about one who had not taken the country, and presented this to Yejong as proof of treason.[3](http://www.e-sejong.co.kr/news/articleView.html?idxno=10354) Another account treats the line nam-i-isip-mideukguk as of uncertain origin, bearing the smell of slander from the aftermath of the case rather than a documented alteration.[4](https://www.m-joongang.com/news/articleView.html?idxno=400786)
## Consequences and political influence
Nam I died in October 1468.[5](http://www.grandculture.net/hwaseong/toc/GC08600609) • [6](https://www.joongang.co.kr/article/25447689) The case completed the removal of the new military leadership that had emerged from the suppression of Yi Si-ae's rebellion, clearing the way for the old ministers around Sin Suk-ju and Han Myeong-hoe, who took the first-grade Idae merit titles for their role in it.[2](https://yongin.grandculture.net/yongin/toc/GC00900697) • [6](https://www.joongang.co.kr/article/25447689) Together with the earlier Guiseong-gun affair, it marked how the rivalry between the senior merit subjects and the young commanders of 1467 was expressed under the new reign.[7](https://contents.history.go.kr/mobile/kc/view.do?code=kc_age_30&levelId=kc_i305100)
Rehabilitation came late. In 1818 (Sunjo 18), at the request of Right State Councillor Nam Gong-cheol, a descendant, the state recognized that Nam I had died through Yu Ja-gwang's false accusation and restored the offices and titles of Nam I and Gang Sun, 350 years after Nam I's death.[5](http://www.grandculture.net/hwaseong/toc/GC08600609) • [6](https://www.joongang.co.kr/article/25447689) Nam I was thereafter enshrined at Gubong Seowon in Changnyeong, Yongmunsa in Yongsan, and Chungminsa in Seongdong, Seoul; the posthumous name Chungmu (忠武) was granted in 1910.[2](https://yongin.grandculture.net/yongin/toc/GC00900697) • [5](http://www.grandculture.net/hwaseong/toc/GC08600609)
## Historians' assessment
The reference works treat the case as a false accusation: Yu Ja-gwang "slandered" Nam I as plotting treason on the strength of an overheard remark about a comet, leading to his execution after interrogation.[1](https://encykorea.aks.ac.kr/Article/E0012096) The case is framed as the elimination of the new men who had risen in suppressing Yi Si-ae's rebellion by the Won-sang faction of Sin Suk-ju and Han Myeong-hoe.[2](https://yongin.grandculture.net/yongin/toc/GC00900697) The legend of General Nam I, transmitted in literature and orally, portrays him as a commander of extraordinary ability who met an unjust death, following the stages of birth, marriage, merit, and death.[8](https://encykorea.aks.ac.kr/Article/E0012106)
Two points remain unsettled between accounts. The year Nam I passed the military examination is given as 1457 (Sejo 3) in one encyclopedia and as 1460 (Sejo 6), at age 20, in another.[2](https://yongin.grandculture.net/yongin/toc/GC00900697) • [5](http://www.grandculture.net/hwaseong/toc/GC08600609) Whether Yu Ja-gwang literally altered Nam I's poem is stated as fact by one account[3](http://www.e-sejong.co.kr/news/articleView.html?idxno=10354) and treated as uncertain tradition by another.[4](https://www.m-joongang.com/news/articleView.html?idxno=400786)
## References
1. [남이 - 한국민족문화대백과사전](https://encykorea.aks.ac.kr/Article/E0012096)
2. [남이 - 디지털용인문화대전](https://yongin.grandculture.net/yongin/toc/GC00900697)
3. [간신배들의 망국 요술 방망이는 아첨과 헛소문 - 세종뉴스](http://www.e-sejong.co.kr/news/articleView.html?idxno=10354)
4. [공주의 손자, 이시애의 난과 건주여진을 평정하다 - 월간중앙](https://www.m-joongang.com/news/articleView.html?idxno=400786)
5. [남이 - 디지털화성시문화대전](http://www.grandculture.net/hwaseong/toc/GC08600609)
6. [하늘 찌른 왕의 총애, 왕 바뀌자마자 역적 몰려 - 중앙일보](https://www.joongang.co.kr/article/25447689)
7. [우리역사넷 - 이시애의 난](https://contents.history.go.kr/mobile/kc/view.do?code=kc_age_30&levelId=kc_i305100)
8. [남이 장군 설화 - 한국민족문화대백과사전](https://encykorea.aks.ac.kr/Article/E0012106)
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*Topic: Encyclopedia › Society and history › History and archaeology › Asian history › Korea › Early Joseon (1392 to 1592) › Events and political conflicts*
*Initially written Sep 24, 2026 · Edited: Oct 15, 2026*
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License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license