{ "id": "ep4vbpf30m", "slug": "hae-gu", "title": "Hae Gu", "updated": "2026-10-15", "topic_path": [ { "id": "society", "label": "Society and history", "api_url": "https://www.edgepedia.org/api/v1/topics/society" }, { "id": "society.history", "label": "History and archaeology", "api_url": "https://www.edgepedia.org/api/v1/topics/society.history" }, { "id": "society.history.asia", "label": "Asian history", "api_url": "https://www.edgepedia.org/api/v1/topics/society.history.asia" }, { "id": "society.history.asia.korea", "label": "Korea", "api_url": "https://www.edgepedia.org/api/v1/topics/society.history.asia.korea" }, { "id": "society.history.asia.korea.kr-three-kingdoms", "label": "Three Kingdoms of Korea (Goguryeo, Baekje, Silla) and Gaya (57 BC to 668)", "api_url": "https://www.edgepedia.org/api/v1/topics/society.history.asia.korea.kr-three-kingdoms" }, { "id": "society.history.asia.korea.kr-three-kingdoms.baekje", "label": "Baekje", "api_url": "https://www.edgepedia.org/api/v1/topics/society.history.asia.korea.kr-three-kingdoms.baekje" } ], "geo": [ { "id": "geo.asia.t500.society.history.asia.korea.kr-three-kingdoms", "label": "Asia (other) · 500 BC to AD 999: Three Kingdoms of Korea (Goguryeo, Baekje, Silla) and Gaya (57 BC to 668)", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t500.society.history.asia.korea.kr-three-kingdoms", "path": [ { "id": "geo.asia", "label": "Asia (other)", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia" }, { "id": "geo.asia.t500", "label": "Asia (other) · 500 BC to AD 999", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t500" }, { "id": "geo.asia.t500.society", "label": "Society and history", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t500.society" }, { "id": "geo.asia.t500.society.history", "label": "History and archaeology", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t500.society.history" }, { "id": "geo.asia.t500.society.history.asia", "label": "Asian history", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t500.society.history.asia" }, { "id": "geo.asia.t500.society.history.asia.korea", "label": "Korea", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t500.society.history.asia.korea" }, { "id": "geo.asia.t500.society.history.asia.korea.kr-three-kingdoms", "label": "Three Kingdoms of Korea (Goguryeo, Baekje, Silla) and Gaya (57 BC to 668)", "api_url": "https://www.edgepedia.org/api/v1/geo/geo.asia.t500.society.history.asia.korea.kr-three-kingdoms" } ] } ], "excerpt": "Hae Gu (해구) was a Baekje official of the Three Kingdoms period who, as military councillor, assassinated King Munju and dominated the court before dying in a failed 478 rebellion.", "snippet": "Hae Gu (해구) was a Baekje official of the Three Kingdoms period who, as military councillor, assassinated King Munju and dominated the court before dying in a failed 478 rebellion.", "node": "society.history.asia.korea.kr-three-kingdoms.baekje", "markdown": "# Hae Gu\n\n**Hae Gu** (해구) was a Baekje official of the [Three Kingdoms](https://www.edgepedia.org/three-kingdoms) period who served as *byeonggwanjwapyeong* (兵官佐平, the councillor in charge of military affairs), assassinated King Munju, dominated the court under the child king Samgeun, and died in 478 when his own rebellion against the royalist Jin clan was suppressed.[1](https://encykorea.aks.ac.kr/Article/E0062433) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409)\n\n| Fact | Detail |\n|---|---|\n| Native name | 해구 (Hae Gu) |\n| State and period | Baekje, Ungjin period |\n| Office | *Byeonggwanjwapyeong* (military affairs councillor), appointed August 476[1](https://encykorea.aks.ac.kr/Article/E0062433) • [3](https://sejong.grandculture.net/sejong/toc/GC07700339) |\n| Killings | Naesinjwapyeong Gonji, 477; King Munju, 477 or 478 (sources differ)[1](https://encykorea.aks.ac.kr/Article/E0062433) • [3](https://sejong.grandculture.net/sejong/toc/GC07700339) |\n| Rebellion | 478, with Eunsol Yeon Sin, based at Daedu fortress[4](https://db.history.go.kr/id/sg_026r_0030_0020) • [1](https://encykorea.aks.ac.kr/Article/E0062433) |\n| Death | 478, killed fighting Jin Ro's 500 elite soldiers[4](https://db.history.go.kr/id/sg_026r_0030_0020) • [1](https://encykorea.aks.ac.kr/Article/E0062433) |\n\n## Origins and family\n\nHae Gu belonged to the Hae clan (해씨), which had emerged as a holder of power in Baekje during King Jeonji's reign in the early fifth century, after the defeat of the Jin clan that had previously led the military confrontation with Goguryeo; the Hae clan took part in decisions on policy toward Goguryeo.[5](https://www.kci.go.kr/kciportal/ci/sereArticleSearch/ciSereArtiView.kci?sereArticleSearchBean.artiId=ART001403737) The Jin clan had been a check on the Hae family since the Hanseong period, and both families produced queens in that era.[1](https://encykorea.aks.ac.kr/Article/E0062433) • [4](https://db.history.go.kr/id/sg_026r_0030_0020)\n\n## Career\n\nHae Gu's rise followed the collapse of Baekje's first capital. Goguryeo forces took Hanseong in 475 and killed King Gaero; his kinsman Munju, who had obtained 10,000 Silla relief troops, took the throne and moved the government to Ungjin (present-day Gongju) in October 475.[6](https://new.baekje-heritage.or.kr/html/en/historic/historic_010102.html) • [7](https://www.ijkaa.org/v.8/0/44/126) • [9](https://encykorea.aks.ac.kr/Article/E0022355) In August 476 (Munju year 2) Hae Gu was appointed *byeonggwanjwapyeong*, and, exploiting the weakened royal authority and political instability of the early Ungjin period, he coveted the throne.[1](https://encykorea.aks.ac.kr/Article/E0062433) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) • [3](https://sejong.grandculture.net/sejong/toc/GC07700339)\n\nIn 477 he killed the *naesinjwapyeong* ([內臣佐平](https://www.edgepedia.org/naesin-jwapyeong)) Gonji, who within the royal house held power exceeding King Munju's, and then monopolized power, disrupted the law, and grew too strong for the king to control.[1](https://encykorea.aks.ac.kr/Article/E0062433) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) The date of the king's own murder is reported differently: the Encyclopedia of Korean Culture and the biographical database place it in the ninth month of 478, when Munju was away hunting and lodging outside, and Hae Gu secretly sent men who killed him and seized full power;[1](https://encykorea.aks.ac.kr/Article/E0062433) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) the Digital Sejong Cultural Encyclopedia dates the assassination to September 477,[3](https://sejong.grandculture.net/sejong/toc/GC07700339) and the official Baekje heritage history, giving Munju's reign as 475–477, also implies 477.[6](https://new.baekje-heritage.or.kr/html/en/historic/historic_010102.html)\n\nThe Jin clan responded by enthroning the thirteen-year-old Samgeun of the Buyeo royal house, and Hae Gu manipulated state power through the child king; the post-capital political contest became a struggle between Hae Gu's faction and an anti-Hae Gu faction centered on the Jin clan of the Yeongi region.[1](https://encykorea.aks.ac.kr/Article/E0062433) • [3](https://sejong.grandculture.net/sejong/toc/GC07700339)\n\n## Political influence\n\nHae Gu held the military power of the state and was behind the assassinations of Gonji and Munju; because Munju's son Samgeun succeeded him as king, however, the Buyeo royal line of Baekje continued.[1](https://encykorea.aks.ac.kr/Article/E0062433) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) • [11](https://www.kci.go.kr/kciportal/ci/sereArticleSearch/ciSereArtiView.kci?sereArticleSearchBean.artiId=ART002381058) His rebellion developed into a civil war between the Hae and Jin clans, the two great aristocratic houses of the Hanseong era.[2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) After the revolt was settled, with Dongseong's accession the Jin clan and new forces around Ungjin emerged as Baekje's ruling group, ending the post-Ungjin turmoil; Dongseong promoted regional forces such as the Sa and Yeon clans of the Geum River basin to balance the old nobility.[3](https://sejong.grandculture.net/sejong/toc/GC07700339) • [8](https://contents.history.go.kr/front/nh/view.do?levelId=nh_006)\n\n## Military style\n\nDriven from the center, his forces joined the local power-holder Eunsol Yeon Sin and secured a base at Daedu fortress, in present-day Yesan County, South Chungcheong Province, according to the biographical database and the Encyclopedia of Korean Culture.[2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) • [1](https://encykorea.aks.ac.kr/Article/E0062433) The rebels were destroyed by 500 elite soldiers under the *deoksol* Jin Ro.[4](https://db.history.go.kr/id/sg_026r_0030_0020) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) \n\n## Death and successors\n\nKing Samgeun ordered Jin Ro to lead 500 elite soldiers against Hae Gu, who died fighting.[4](https://db.history.go.kr/id/sg_026r_0030_0020) • [1](https://encykorea.aks.ac.kr/Article/E0062433) Yeon Sin fled to Goguryeo, and his wife and children were captured and beheaded at the market in Ungjin.[4](https://db.history.go.kr/id/sg_026r_0030_0020) • [3](https://sejong.grandculture.net/sejong/toc/GC07700339) Samgeun died after a reign of three years.[9](https://encykorea.aks.ac.kr/Article/E0022355) • [6](https://new.baekje-heritage.or.kr/html/en/historic/historic_010102.html)\n\n## Historians' assessment\n\nReference works classify Hae Gu as a rebel and a disturber of the state, an official who turned against the throne he was appointed to serve.[1](https://encykorea.aks.ac.kr/Article/E0062433) The year of King Munju's assassination is given as 478 by the Encyclopedia of Korean Culture and the biographical database,[1](https://encykorea.aks.ac.kr/Article/E0062433) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) but as 477 by the Sejong encyclopedia and the Baekje heritage history.[3](https://sejong.grandculture.net/sejong/toc/GC07700339) • [6](https://new.baekje-heritage.or.kr/html/en/historic/historic_010102.html) The rebel base is likewise given as Daedu-seong in Yesan County by two sources[1](https://encykorea.aks.ac.kr/Article/E0062433) • [2](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409) and as Daedusan Fortress identified with Asan by a third.[3](https://sejong.grandculture.net/sejong/toc/GC07700339)\n\n## Legacy\n\nThe instability left by Munju's assassination and Hae Gu's rebellion shaped the court that followed: it is cited as the background to Baek Ga's appointment as *wisa jwapyeong*, commander of the royal guards.[10](https://doi.org/10.18347/hufshis.2025.94.39) More broadly, the destruction of the Hae faction opened the way for Dongseong's balancing of old Hanseong nobles against new Geum River basin families such as the Sa and Yeon clans, shifting political initiative to the new aristocrats.[8](https://contents.history.go.kr/front/nh/view.do?levelId=nh_006) • [9](https://encykorea.aks.ac.kr/Article/E0022355)\n## References\n\n1. [해구 - 한국민족문화대백과사전 (Encyclopedia of Korean Culture)](https://encykorea.aks.ac.kr/Article/E0062433)\n2. [해구, 한국역대인물 종합정보 시스템 (Academy of Korean Studies)](http://people.aks.ac.kr/front/dirSer/ppl/pplView.aks?pplId=PPL_2BKJ_A9999_1_0014409)\n3. [해구의 반란 - 디지털세종시문화대전](https://sejong.grandculture.net/sejong/toc/GC07700339)\n4. [삼국사기, 삼근왕 2년 해구의 반란, 한국 고대 사료 DB](https://db.history.go.kr/id/sg_026r_0030_0020)\n5. [百濟 腆支王代 解氏勢力의 擡頭와 對高句麗 政策 (KCI)](https://www.kci.go.kr/kciportal/ci/sereArticleSearch/ciSereArtiView.kci?sereArticleSearchBean.artiId=ART001403737)\n6. [Revival and Development of Baekje, Baekje Historic Areas](https://new.baekje-heritage.or.kr/html/en/historic/historic_010102.html)\n7. [National Museum of Korea, Journal of Korean Art and Archaeology](https://www.ijkaa.org/v.8/0/44/126)\n8. [우리역사넷 (Korean History Education Portal)](https://contents.history.go.kr/front/nh/view.do?levelId=nh_006)\n9. [백제 - 한국민족문화대백과사전](https://encykorea.aks.ac.kr/Article/E0022355)\n10. [The Political Status of Baek Ga during the Reign of King Dongseong of Baekje](https://doi.org/10.18347/hufshis.2025.94.39)\n11. [일본 사료로 본 백제 熊津시기 왕계](https://www.kci.go.kr/kciportal/ci/sereArticleSearch/ciSereArtiView.kci?sereArticleSearchBean.artiId=ART002381058)\n\n---\n*Topic: Encyclopedia › Society and history › History and archaeology › Asian history › Korea › Three Kingdoms of Korea (Goguryeo, Baekje, Silla) and Gaya (57 BC to 668) › Baekje*\n\n*Initially written Sep 24, 2026 · Edited: Oct 15, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n", "same_as": [], "url": "https://www.edgepedia.org/hae-gu", "markdown_url": "https://www.edgepedia.org/hae-gu.md", "license": { "name": "Edgepedia Community License 1.0", "url": "https://www.edgepedia.org/edgepedia/license", "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.", "spdx": "LicenseRef-Edgepedia-Community-1.0" }, "credit": "\"Hae Gu\", Edgepedia (EdgeChat), https://www.edgepedia.org/hae-gu. Edgepedia Community License 1.0.", "credit_md": "\"[Hae Gu](https://www.edgepedia.org/hae-gu)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/hae-gu](https://www.edgepedia.org/hae-gu). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).", "credit_html": "\"Hae Gu\", Edgepedia (EdgeChat), https://www.edgepedia.org/hae-gu. Edgepedia Community License 1.0.", "speakable": "Hae Gu was a Baekje official of the Three Kingdoms period who, as military councillor, assassinated King Munju and dominated the court before dying in a failed 478 rebellion." }