Aug. 21, 1983: Opposition leader Benigno Aquino shot dead on arrival at Manila International Airport after returning from self-imposed exile in the United States. Oct. 23, 1984: Five-member commission of inquiry that had been nominated by government implicates 25 military men (including Chief of Staff Gen. Fabian Ver) and one civilian in murder of Mr. Aquino. May 14, 1984: National Assembly elections give surprising boost to opposition, which wins 59 of 183 elective seats -- up from 14 seats in 1978. Jan. 24, 1985: Fact-finding board formally charges Ver and 25 others with conspiracy to murder Aquino. Trial begins one week later. Nov. 3, 1985: President Ferdinand Marcos announces presidential election to be held in early 1986. Dec. 2, 1985: General Ver and 25 others accused in Aquino assassination acquitted by special court. Dec. 3, 1985: Corazon Aquino (widow of Benigno Aquino) declares her candidacy for presidency. Feb. 7, 1986: Voters go to the polls. Citizen poll-watchers report incidents of harassment and fraud. Feb 8-10: Both sides claim they are leading in the tally. Mrs. Aquino demands that Mr. Marcos concede, and Marcos hints he may invalidate the election. International observers report election was marked by widespread fraud. Feb. 11: President Reagan suggests that election fraud may have taken part on both sides. His remarks interpreted in Philippines as supporting Marcos. Feb. 15: National Assembly proclaims Marcos winner. Election observers continue to claim results are flawed. Reagan blames Marcos for fraud. Feb. 16: Aquino announces civil disobediance campaign to bring down Marcos government. Feb. 19: US Secretary of State George Shultz assails ``fraud and violence on a systematic and widespread scale'' in the election by Marcos supporters. Feb. 22: Defense Minister Juan Ponce Enrile and Lieut. Gen. Fidel Ramos resign from the Marcos government and barricade themselves in Defense Ministry. Later they move to Camp Crame, across the street. They call for Marcos to step down. Feb. 23: Military forces advancing on fort where Enrile, Ramos, and other defectors are staying retreat in the face of massive civilian opposition. Feb. 24: Marcos declares state of emergency and says he will not step down. Aquino supporters declare a provisional government with Aquino as President. Reagan administration says Marcos should step down and threatens to stop military aid. Feb. 25: Marcos, only hours after being inaugurated to fourth term, leaves office, and is flown to US air force base near Manila. Aquino, who had formed provisional government and taken presidential oath, is recognized officially by the US as President of the Philippines.