During the Martial Law years from 1972-1981, President Marcos issued Proclamation 1081 placing the Philippines under martial law, citing threats from communists and anti-Marcos demonstrations. He arrested opposition leaders and activists and established a constitutional convention to frame a new constitution concentrating power in the presidency. Some achievements included educational reforms but he also censored media. After lifting Martial Law in 1981, Marcos retained power through a controversial election in 1986 and the assassination of opponent Ninoy Aquino. Large protests erupted after the disputed election results, leading to Marcos' exile and Corazon Aquino's induction as president.