The May 16 military coup d'état () was a military coup d'état in South Korea in 1961, organized and carried out by Park Chung-hee and his allies who formed the Military Revolutionary Committee, nominally led by Army Chief of Staff Chang Do-yong after the latter's acquiescence on the day of the coup. The coup rendered powerless the democratically elected government of Prime Minister Chang Myon and President Yun Posun, and ended the Second Republic, installing a reformist military Supreme Council for National Reconstruction effectively led by Park, who took over as chairman after General Chang's arrest in July. The coup was instrumental in bringing to power a new developmentalist elite and in laying the foundations for the rapid industrialization of South Korea under Park's leadership, but its legacy is controversial for the suppression of democracy and civil liberties it entailed, and the purges enacted in its wake. Termed the "May 16 Military Revolution" by Park and his allies, "a new, mature national debut of spirit", the coup's nature as a "revolution" is controversial and its evaluation contested. Background and causes The background to the coup can be analysed both in terms of its immediate context, and the broader setting of the development of post-liberation South Korea. While the Second Republic presented South Korea with a singularly problematic economic and political climate which encouraged a military intervention, the direct roots of the coup stretch back to the late Rhee period, and more recent historians such as Yong-Sup Han argue that the frequently recurring image of the coup as an inevitable direct response purely to the vagaries of a new regime paralyzed by endemic instability is over-simplistic. South Korea under Syngman Rhee From 1948, South Korea was governed by President Syngman Rhee, an anti-Communist who used the Korean War to consolidate a monopoly on political power in the republic. Rhee represented the interests of a conservative ruling class, the so-called "liberation aristocrats" who had risen to positions of influence under American occupation. These "liberation aristocrats" formed the bulk of the political class, encompassing both Rhee's supporters and his rivals in the Democratic Party, which advanced a vision of society broadly similar to his own. Rhee eliminated any significant source of real opposition, securing for example the execution of Cho Bong-am, who had campaigned against him in the presidential elections of 1956 on a platform of peaceful reunification and had attracted some 30%