Supreme Council for National Reconstruction

The First Republic of Korea was established on 15 August 1948 following the transfer of power from the United States Army Military Government in Korea (USAMGIK) to the Government of South Korea, becoming the first independent government of South Korea. The First Republic had a highly-centralized government under President Syngman Rhee, who maintained autocratic power as the President of South Korea, and was widely viewed as authoritarian and corrupt. Rhee's government was characterized by widespread cronyism and indifference to South Korea's economic development. Until the late 1950s, Rhee's unpopularity and corruption was largely tolerated by the South Korea public for the sake of political unity, and as a staunch anti-communist, had crushed open opposition to his regime using the threat of communism as an excuse. In April 1960, Rhee was eventually overthrown in mass protests known as the April Revolution, started in response to the murder of a student killed by police during earlier protests against election rigging. Rhee's former political opponents in the Democratic Party established the Second Republic of Korea, with new parliamentary system of government, and dominated the National Assembly following elections. The Second Republic was led by Chang Myon as Prime Minister of South Korea, a position which held most of the power, and was headed by Yun Bo-seon as President, now a largely ceremonial role. The new government attempted to fix the issues left behind by Rhee, but proved to be ineffective, and caused the political instability of the First Republic to continue.

Many high-ranking figures of the South Korean military held animosity for so-called "liberation aristocrats" – the ruling class of conservative politicians involved in the Korean independence movement and the USAMGIK – that they blamed for the stalling of development in South Korea. Military figures noted how South Korea had been intensively developed under the Japanese colonial system and the "economic miracle" occurring in Japan, in marked contrast to Rhee's presidency which saw little significant effort to develop the economy, which remained stagnant, poor and largely agrarian. The lack of development under Rhee provoked a growing nationalistic intellectual reaction which called for a radical restructuring of society and a thorough political and economic reorganization, rejecting the model being pursued by the governing elite.

General Chang Do-yong served as the first Chairman of the Supreme Council from May to July 1961.

Park Chung-hee, a Major General in the Republic of Korea Army with decidedly ambiguous political leanings, was heavily influenced by this unfolding intellectual reaction. Park became the leader of a reformist faction within the military that plotted a coup d'etat against the civilian government of the Second Republic on 12 May 1961. The plot was aborted after being leaked, however, the military attempted another coup four days later on 16 May which was successful, dissolving the Second Republic. They proceeded to broadcast a proclamation outlining the policy objectives of the coup, including anti-communism, strengthening of ties with the United States, the elimination of political corruption, the construction of an autonomous national economy, Korean reunification, and the removal of the present generation of politicians. Park and his supporters subsequently established the Military Revolutionary Committee as a military junta government, later renamed the Supreme Council for National Reconstruction. President Yun Posun, who had sided with the coup, was retained in his position as a figurehead. General Chang Do-yong, the Army Chiefs of Staff, was installed as the Chairman of the Supreme Council, while Park became the Vice-Chairman. However, the power struggles within the Supreme Council allowed Park to engineer the gradual transfer of power from Chang to himself. In July, Park officially replaced Chang as Chairman, effectively becoming the de facto dictator of Korea.

By 1962, Park and the Supreme Council were coming under increasing pressure by the United States administration of President John F. Kennedy to return to civilian rule, as military leaders had promised to return the government to a democratic system as soon as possible. On December 2, 1962, a referendum was held on returning to a presidential system of rule, which was allegedly passed with a 78% majority.[1] In response, Park eventually abdicated from his military position to be eligible to run as a civilian in the upcoming presidential election, despite he and the other military leaders pledging not to run for office. Park narrowly won in the presidential election of October 1963, and replaced Yun Posun as the President of Korea. The Supreme Council was officially dissolved upon the inauguration of the Third Republic of Korea on 17 December 1963, ending the three-year constitutional vacuum.[1]