Sejo of Joseon (2 November 1417 – 23 September 1468), personal name Yi Yu (

Korean Korean may refer to: People and culture * Koreans, ethnic group originating in the Korean Peninsula * Korean cuisine * Korean culture * Korean language **Korean alphabet, known as Hangul or Chosŏn'gŭl **Korean dialects and the Jeju language ** ...

: 이유;

Hanja Hanja (Hangul: ; Hanja: , ), alternatively known as Hancha, are Chinese characters () used in the writing of Korean. Hanja was used as early as the Gojoseon period, the first ever Korean kingdom. (, ) refers to Sino-Korean vocabulary, ...

: 李瑈), sometimes known as Grand Prince Suyang (

: 수양대군;

: 首陽大君), was the seventh ruler of the

Joseon dynasty Joseon (; ; Middle Korean: 됴ᇢ〯션〮 Dyǒw syéon or 됴ᇢ〯션〯 Dyǒw syěon), officially the Great Joseon (; ), was the last dynastic kingdom of Korea, lasting just over 500 years. It was founded by Yi Seong-gye in July 1392 and r ...

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

. He was the second son of Sejong the Great and the uncle of King Danjong, against whom he led a ''

coup d'état A coup d'état (; French for 'stroke of state'), also known as a coup or overthrow, is a seizure and removal of a government and its powers. Typically, it is an illegal seizure of power by a political faction, politician, cult, rebel group, m ...

'' in 1455.

Biography

Early life

Born in 1417 as the fourth child and second son of Grand Prince Chungnyeong (future

King Sejong Sejong of Joseon (15 May 1397 – 8 April 1450), personal name Yi Do (Korean: 이도; Hanja: 李祹), widely known as Sejong the Great (Korean: 세종대왕; Hanja: 世宗大王), was the fourth ruler of the Joseon dynasty of Korea. Initial ...

) by his primary wife, Lady Shim of the Cheongsong Shim clan (future

Queen Soheon Queen Soheon (소헌왕후 심씨, 12 October 1395 – 19 April 1446), of the Cheongsong Sim clan, was a posthumous name bestowed to the wife and queen consort of Yi Do, King Sejong and the mother of Yi Hyang, King Munjong and Yi Yu, King Sejo ...

), he showed great ability at archery, horse riding and martial arts, and was also a brilliant military commander, though he never went to the battlefront himself. In 1428, he received the title Grand Prince Suyang by which he is better known.

Rise to power

Following the death of King Sejong in 1450, Suyang's ill brother, Yi Hyang (later known as King Munjong), took the throne but died two years later, and the crown passed to his 12-year-old son, Yi Hong-wi (posthumously named King Danjong). The new monarch was too young to rule the nation, and the government was controlled by

Chief State Councillor Chief may refer to: Title or rank Military and law enforcement * Chief master sergeant, the ninth, and highest, enlisted rank in the U.S. Air Force and U.S. Space Force * Chief of police, the head of a police department * Chief of the boa ...

Hwangbo In and General Gim Jong-seo, who was the Left State Councillor. As Gim Jong-seo and his faction used the chance to extend the power of court officials against royal family members, the tension between him and Suyang greatly increased; not only Suyang himself, but his younger brother, Grand Prince Anpyeong, also sought an opportunity to take control of the country. In order to court the support of the

Ming dynasty The Ming dynasty (), officially the Great Ming, was an imperial dynasty of China, ruling from 1368 to 1644 following the collapse of the Mongol-led Yuan dynasty. The Ming dynasty was the last orthodox dynasty of China ruled by the Han peo ...

, Suyang became an ambassador in 1452. He also surrounded himself with trusted allies, including his famous tactician,

Han Myeong-hoe Han Myeong-hoe (Hangul: 한명회, Hanja: 韓明澮; 26 November 1415 – 28 November 1487) was a Korean politician and soldier during the Joseon period. He was the most trusted tactician of Grand Prince Suyang during the 1453 coup and the sub ...

, who advised him to take over the government in a coup. In 1453, Suyang killed Gim Jong-seo and his faction, thereby taking the reins of power into his own hands. After the coup, he arrested his own brother, Grand Prince Anpyeong, first sending him into exile, then sentencing him to death.

Reign

Finally, in 1455 Suyang forced the powerless king to abdicate, declaring himself the new ruler of Joseon (today known by the

temple name Temple names are posthumous titles accorded to monarchs of the Sinosphere for the purpose of ancestor worship. The practice of honoring monarchs with temple names began during the Shang dynasty in China and had since been adopted by other dyna ...

"Sejo"). After his younger brother Grand Prince Geumsung, and six scholars, including Seong Sam-mun, Park Paeng-nyeon and

Yi Gae Yi Gae (; 1417–1456) was a scholar-official of the Joseon Dynasty who came from the yangban family Hansan Yi clan and one of the six martyred ministers. He was the great-grandson of Goryeo period philosopher Yi Saek and third cousin of Yi ...

, plotted to remove him from power in an attempt to put his nephew back on the throne, Suyang demoted the former king from "King Emeritus" (''Sangwang''; 상왕, 上王) to "Prince Nosan" (''Nosan Gun''; 노산군, 魯山君) and later ordered him to commit suicide by poison. Despite having snatched the throne from his young nephew and killing many people in the process, Sejo proved himself one of the ablest rulers and administrators in Korean history. First, he continued King Taejong's legacy of strengthening the monarchy by weakening the power of the State Council and bringing the officials directly under the king's control. He also further developed the administrative system, which had also been introduced by Taejong, enabling the government to determine exact population numbers and to mobilize troops effectively (this caused Yi Si-ae's Rebellion, which he suppressed). Just like Taejong, Sejo was a hardliner concerning foreign policy and attacked the

Jurchens Jurchen (Manchu: ''Jušen'', ; zh, 女真, ''Nǚzhēn'', ) is a term used to collectively describe a number of East Asian Tungusic-speaking peoples, descended from the Donghu people. They lived in the northeast of China, later known as Manch ...

on the northern front in 1460 (오랑캐, 兀良哈) and 1467 (호리개, 胡里改). He also revised the land ordinance to improve the national economy and encouraged the publication of history, economy, agriculture, and religion books. Sejo himself compiled a number of books based on his interests. One of them is '' Seokbosangjeol'', a biography of

Gautama Buddha Siddhartha Gautama, most commonly referred to as the Buddha, was a wandering ascetic and religious teacher who lived in South Asia during the 6th or 5th century BCE and founded Buddhism. According to Buddhist tradition, he was born in Lu ...

. The others are ''Worinseokbo'' (월인석보, 月印釋譜) and ''Yeokdaebyeongyo'' (역대병요, 歷代兵要). Most importantly, he compiled the Grand Code for State Administration, which became the cornerstone of dynastic administration and provided the first form of written constitutional law in Korea.

Death

Sejo died in 1468, and the throne passed to his sickly second son, Yi Hwang (

Yejong of Joseon Yejong of Joseon (12 February 1450 – 31 December 1469), personal name Yi Hwang ( Korean: 이황; Hanja: 李晄), firstly titled Grand Prince Haeyang ( Korean: 해양대군; Hanja: 海陽大君), was the eighth ruler of the Joseon dynasty o ...

). His tomb is known as ''Gwangneung'' (광릉) and is located in

Namyangju Namyangju () is a city in Gyeonggi Province, South Korea. To the east is Gapyeong County, to the west is Guri City, and to the north is Pocheon City. Namyangju-si was originally a southern part of Yangju-gun, but was separated into Namyangju-gu ...

Gyeonggi Province Gyeonggi-do (, ) is the most populous province in South Korea. Its name, ''Gyeonggi'', means "京 (the capital) and 畿 (the surrounding area)". Thus, ''Gyeonggi-do'' can be translated as "Seoul and the surrounding areas of Seoul". Seoul, the na ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korean Peninsula and sharing a land border with North Korea. Its western border is formed by the Yellow Sea, while its eas ...

Family

*Father: King Sejong of Joseon (조선 세종) (15 May 1397 – 8 April 1450) **Grandfather: King Taejong of Joseon (조선 태종) (13 June 1367 – 30 May 1422) **Grandmother:

Queen Wongyeong Queen Wongyeong (원경왕후 민씨; 29 July 1365 – 18 August 1420) of the Yeoheung Min clan, was the primary wife of Taejong of Joseon, and the mother of Sejong the Great. She was queen consort of Joseon from 1400, and was honored as Queen J ...

of the

Yeoheung Min clan The Yeoheung Min clan () is a Korean clan that traces its origin to Yeoju, Gyeonggi Province. The 2015 Korean Census counted 167,124 members of the Yeoheung Min clan. Origin The Yeoheung Min clan's progenitor was Min Ching-do (민칭도, 閔� ...

(원경왕후 민씨) (29 July 1365 – 18 August 1420) *Mother: Queen Soheon of the Cheongsong Shim clan (소헌왕후 심씨) (12 October 1395 – 19 April 1446) **Grandfather: Shim On (심온) (1375 – 18 January 1419) **Grandmother: Lady Ahn of the Sunheung Ahn clan (순흥 안씨) (? – 1444) Consorts and their respective issue(s): # Queen Jeonghui of the Papyeong Yun clan (정희왕후 윤씨) (8 December 1418 – 6 May 1483) ## Yi Jang, Crown Prince Uigyeong (의경세자 이장) (1438 – 2 September 1457), first son ## Princess Uiryeong (의령공주), first daughterAs a legitimate daughter of the king, her title properly translates to "Royal Princess" (''Gongju''; 공주, 公主). — Disputed. ## Princess Uisuk (의숙공주) (1442 – 3 December 1477), second daughter ## Yi Hwang, Grand Prince Haeyang (해양대군 이황) (14 January 1450 – 31 December 1469), third son # Royal Noble Consort Geun of the Seonsan Park clan (근빈 박씨) (1425 – ?) ## Yi Seo, Prince Deokwon (덕원군 이서) (6 March 1449 – 22 July 1498), second son ## Yi Seong, Prince Changwon (창원군 이성) (1458 – 1484), fourth son # Deposed Royal Consort So-yong of the Park clan (폐소용 박씨) (? – 1465)She was executed by hanging in the 11th year of Sejo’s reign. ## Prince Yi A-ji (왕자 이아지) (1459 – 1563), fifth son

Ancestry

In popular culture

* Portrayed by Kim Al-eum in the 1983 MBC TV series ''

The King of Chudong Palace ''The King of Chudong Palace'' () is a 1983 South Korean historical television series, the first installment of the drama series ''500 Years of Joseon Dynasty'' by director Lee Byung-hoon and writer Shin Bong-seung. It aired on MBC from March ...

''. * Portrayed by Nam Sung-woo in the 1984–1985 MBC TV series ''500 Years of Joseon: The Ume Tree in the Midst of the Snow''. * Portrayed by Seo In-seok in the 1994

KBS2 The Korean Broadcasting System (KBS) () is the national broadcaster of South Korea. Founded in February 1927, it is one of the leading South Korean television and radio broadcasters. KBS operates seven radio networks, ten television channels, a ...

TV series ''Han Myung-hoi''. * Portrayed by Im Dong-jin in the 1998–2000

KBS1 The Korean Broadcasting System (KBS) () is the national broadcaster of South Korea. Founded in February 1927, it is one of the leading South Korean television and radio broadcasters. KBS operates seven radio networks, ten television channels, ...

TV series '' The King and Queen''. * Portrayed by Choi Bong-sik in the 2007

TV series ''Sayuksin''. * Portrayed by Kim Byung-se in the 2007–2008 SBS TV series '' The King and I''. * Portrayed by Kim Yeong-cheol in the 2011

TV series '' The Princess' Man.'' * Portrayed by Kim Young-ho in the 2011

JTBC JTBC (shortened from ''Joongang Tongyang Broadcasting Company'' (; stylized as jtbc) is a South Korean nationwide pay television network. Its primary shareholder is JoongAng Holdings, with a 25% stake. It was launched on 1 December 2011. JTB ...

TV series '' Insu, The Queen Mother''. * Portrayed by

Lee Jung-jae Lee Jung-jae (; born December 15, 1972) is a South Korean actor and filmmaker. Considered one of the most successful actors in South Korea, he has received various accolades, including a Primetime Emmy Award, a Screen Actors Guild Award, a Cri ...

in the 2013 film '' The Face Reader''. * Portrayed by Go Young-bin in the 2016

TV series ''

Jang Yeong-sil Jang Yeong-sil (; ; 1390 – after 1442) was a Korean mechanical engineer, scientist, and inventor during the Joseon Dynasty (1392–1897). Although Jang was born as a peasant, King Sejong allowed Jang to work at the royal palace. Jang's inven ...

''. *Portrayed by Park Hee-soon in the 2019 film '' Jesters: The Game Changers''.

Notes

{{Authority control 1417 births 1468 deaths 15th-century Korean monarchs Joseon Buddhists Korean Buddhist monarchs Regents of Korea People from Seoul