South Korea's history: a constitution written against its own presidents

Who ruled Korea before the republic

The peninsula was inhabited as early as the Lower Palaeolithic. Korean founding mythology dates the first kingdom, Gojoseon, to 2333 BC; Chinese records note it in the seventh century BC. From the first century BC the rival kingdoms of Goguryeo, Baekje and Silla divided the peninsula between them, until Silla unified most of it in 676.

Three long dynasties followed. Goryeo reunited the Later Three Kingdoms in 936 and gave the country the name that visiting Arab and Persian merchants pronounced as "Korea". It survived three decades of Mongol invasion in the thirteenth century by submitting as a tributary ally of the Yuan. In 1392 a general sent to attack China, Yi Seong-gye, turned his army round, took power and founded Joseon, with its capital at Hanseong, the site of Seoul.

Joseon lasted until 1897. King Sejong created the Hangul alphabet to spread literacy beyond the scholarly class. Japan invaded between 1592 and 1598 and was pushed back by the Joseon navy under Admiral Yi Sun-sin, civilian militias and Ming troops; the Manchus invaded in 1627 and 1637. By the nineteenth century the court's isolation had earned it the nickname "the hermit kingdom", and treaties with Japan in 1876 and the United States in 1882 forced its ports open. In 1897 King Gojong proclaimed the Korean Empire.

How Japan ruled Korea for thirty-five years

Japan made Korea a protectorate under a treaty of 1905, forced Gojong to abdicate in 1907 and annexed the country in 1910. For thirty-five years it was governed as the colony of Chōsen by a Governor-General in Keijō, the Japanese name for Seoul.

The colonial state built railways, ports and roads, and it set out to assimilate the population. From 1939 Koreans were made to give up clan-based family names for new surnames in the family register, and the Korean language was eventually all but banned. The same year Japan began mobilising Koreans for its war effort, around 5.4 million of them, and many women and girls were forced into sexual slavery as "comfort women" for Japanese soldiers. The March First Movement protests of 1919 were followed by resistance groups in exile, among them a Provisional Government of the Republic of Korea based in China.

How that period is remembered remains a live dispute between the two states. The Treaty on Basic Relations of 1965 established working diplomatic ties and declared every treaty between the empires of Japan and Korea "already null and void". It brought Japanese loans and compensation, came without an official apology from the Japanese government, and set off protests across South Korea. Relations have moved between warmer and cooler periods since, often over the history of those years.

Why Korea was divided after Japan surrendered

Japan's surrender in August 1945 left about 700,000 Japanese to be disarmed and repatriated. Two Americans, Dean Rusk and Charles Bonesteel, proposed the 38th parallel as the line between an American and a Soviet occupation zone because it put Seoul on the American side, and the Soviets accepted. The division was meant to be temporary, pending a four-power trusteeship.

A joint US-Soviet commission deadlocked, and in September 1947 the United States took the question to the United Nations. The North refused a UN-supervised vote, so a Constitutional Assembly was elected in the South alone in May 1948. It adopted a constitution on 12 July, and the Republic of Korea was proclaimed on 15 August 1948; the Democratic People's Republic followed in the North on 9 September. A UN General Assembly resolution of 12 December 1948 recognised the Seoul government as the lawful one where the UN commission had been able to observe.

The new state began at war with part of its own population. Risings in Jeju, Yeosu and Suncheon in 1948 were put down at a cost given in the History of South Korea article as 14,000 to 60,000 lives. Britannica counts almost 8,000 members of the southern security forces and at least 30,000 other Koreans dead in the partisan war before 1950. A land reform enacted in June 1949 made about 40% of farm households small owners.

What the Korean War left behind

North Korean forces crossed the parallel before dawn on 25 June 1950 and entered Seoul three days later. The Soviet Union was boycotting the Security Council, so no veto stopped the resolution of 27 June asking members to help defend the South, and a United Nations Command of sixteen members led by the United States went to war. China entered on the North's side late in 1950, and the front settled close to where it had started.

The armistice was signed at Panmunjom on 27 July 1953. South Korea never signed it, no peace treaty followed, and the Demilitarized Zone near the old line became the de facto border. The dead are counted differently: Britannica gives at least 2.5 million lives lost, the Wikipedia country article about 3 million, and the US Department of Defense counts 36,574 American service members.

The war's civilian record includes killings by every side. Retreating southern forces executed tens of thousands of suspected communists in the Bodo League massacre. South Korean paramilitaries killed thousands of civilians at Taejŏn, a crime blamed on the North by South Korean and US authorities for half a century, and US troops and aircraft fired on refugees at Nogun-ri in July 1950.

How two presidents rewrote the rules to stay

The constitution of 1948 was amended eight times before 1987. The republics that the country numbers are the result, and in the first four decades most of them ended with the president who shaped them.

How Syngman Rhee lost power to the students

Syngman Rhee, chosen by the assembly in 1948, declared martial law in Busan in May 1952 and arrested opposition members of parliament while he pushed through an amendment making the presidency directly elected. After winning back parliament in 1954 he passed another exempting himself from the eight-year term limit, and he was re-elected in 1956.

The March 1960 election was rigged. Protests began in Masan on polling day and spread nationwide after the body of a student was found in the harbour. On 19 April students marched in Seoul and the government met them with martial law and gunfire; after professors joined the protests on 25 April, Rhee resigned on 26 April and left for exile. The Second Republic that followed was the only parliamentary cabinet system the country has had. About 2,000 demonstrations were held in its eight months, and the hwan lost half its value against the dollar between the autumn of 1960 and the spring of 1961.

How Park Chung Hee made his rule permanent

Major General Park Chung Hee took power in a coup on 16 May 1961, created the Korean Central Intelligence Agency the next month, and won the presidency narrowly in 1963 after a referendum returned the country to a presidential system. His governments ran five-year development plans built on export industry and cheap bank loans to the firms that became the chaebol, normalised relations with Japan, and sent 300,000 soldiers to the Vietnam War between 1964 and 1973.

Park took 51.4% of the vote in 1967. In 1969 an amendment forced through the National Assembly let him seek a third term, which he won in 1971. On 17 October 1972 he declared martial law, dissolved the assembly and suspended the constitution; the Yushin constitution adopted on 21 November gave the president six-year terms with no limit on re-election, chosen indirectly by an electoral college. Emergency decrees in 1974 and 1975 jailed hundreds of dissidents. On 26 October 1979 Park was assassinated by the director of the KCIA, Kim Jae-gyu, which ended eighteen years of military-led rule.

How Gwangju and the June protests ended military rule

Major General Chun Doo-hwan seized control of the army in the coup of 12 December 1979 and on 17 May 1980 extended martial law to the whole country, closing universities and arresting opposition leaders. In Gwangju, students demonstrating on 18 May were attacked by paratroopers, citizens armed themselves, and the army retook the city on 27 May. The government put the dead at 165; later scholarship cited in the Gwangju Uprising article estimates between 600 and 2,300. Chun was then chosen president indirectly under a new constitution of 1980 that allowed one seven-year term.

On 14 January 1987 Park Jong-chul, a Seoul National University student, died under police torture, and a cover-up was exposed by the Catholic Priests Association for Justice in May. When the ruling party named Roh Tae-woo as Chun's successor on 10 June, rallies were held in 18 cities that day. On 18 June about 1.5 million people marched against tear gas, and office workers in shirts and ties joined the students. On 29 June Roh announced that the next president would be directly elected.

A revised constitution was approved by referendum in October 1987 and entered into force on 25 February 1988. It limits the president to one five-year term, lets the National Assembly end martial law by a majority vote, and in Article 128 provides that an amendment extending the presidential term or allowing re-election cannot apply to the president in office when it is proposed. The rule was not new: the 1980 text already kept any extension from benefiting the sitting president. Roh won the December election with about 36% against a divided opposition.

How impeachment replaced the coup

The Sixth Republic has seen presidents leave office on schedule and, twice, early through the courts. Kim Young-sam took office in 1993 as the first civilian president in thirty years, and in December 1996 Chun and Roh were sentenced to prison, Chun among other things for Gwangju. Roh Tae-woo's government had already opened diplomatic ties with the Soviet Union and China after the Seoul Olympics of 1988, and in 1991 both Koreas joined the United Nations at the same time. Kim Young-sam's government held local government elections in 1995 and took the country into the OECD in 1996, a year before the financial crisis that sent it to the International Monetary Fund.

The election of Kim Dae-jung in December 1997, in the middle of that crisis, was the first peaceful transfer of power between parties. Kim had once been a political prisoner under sentence of death. His Sunshine Policy of engagement led to a summit in Pyongyang in June 2000 and to reunions of families separated by the war, and he received the Nobel Peace Prize that year.

The Constitutional Court has decided three presidential impeachments. It reinstated Roh Moo-hyun in May 2004, two months after the assembly voted to remove him. It upheld the impeachment of Park Geun-hye, Park Chung Hee's daughter, on 10 March 2017 after months of weekly protests over the influence of her friend Choi Soon-sil, which the protesters counted at more than 2.3 million people at their peak. She was later sentenced to 24 years in prison for abuse of power and corruption.

The third came from a martial law declaration. At about 10.25 pm on 3 December 2024, Yoon Suk Yeol declared martial law and sent troops to the National Assembly. Legislators got through the cordon, and at 1.00 am on 4 December they voted 190 to 0 to end it; Yoon lifted it shortly before 4.30 am. The assembly impeached him on 14 December with 204 votes, and on 4 April 2025 the Constitutional Court removed him unanimously, eight justices to none. A snap presidential election followed, and its winner took office on 4 June 2025. On 19 February 2026 Yoon was convicted of leading an insurrection and sentenced to life imprisonment.