The May 16 coup was a military coup d'?tat 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 Yun Bo-seon 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.