1912 ANC founded. 1949 Program of Action, including nonviolent civil disobedience, starts. 1953 Civil disobedience. Discontinued when South African government passed law providing stiff penalties for those who break even minor laws. 1959 All-black Pan-African Congress (PAC) forms in protest of ANC's multiracial membership. March 1960: Nationwide passive resistance demonstrations. 69 killed at Sharpeville. South Africa declares state of emergency. April 8, 1960: ANC, declared illegal, goes underground. Dec. 1961: ANC leader Nelson Mandela forms military wing of the ANC. The group begins its sabotage campaign. 1963 South African police find underground ANC headquarters in Johannesburg suburb of Rivonia. 1964 Mandela convicted at Rivonia trial and is given a life sentence. 1976 African riot in Soweto against forced use of Afrikaans language in school curriculum. Thousands of school-age children flee South Africa; many link up with ANC forces outside the country. June 1980: Bombing of Sasol, South Africa's oil-from-coal refinery. August 1981: Rocket attack on Voortrekkerhoogte, Pretoria, center of country's military establishment. Dec. 9, 1982: South Africa, in retaliation for alleged ANC sabotage staged from bases in Lesotho, attacks ANC residences in Lesotho capital of Maseru. 40 killed. Dec. 18, 1982: Bombing of South Africa's only nuclear power station at Koeberg, outside Cape Town. May 20, 1983: Car bomb explodes outside Air Force Headquarters, Pretoria. 17 killed, more than 200 injured in worst sabotage incident in South African history. May 23, 1983: South Africa retaliates with air strike against suspected ANC targets in Mozambique's capital. 6 killed, more than 20 wounded. June 9, 1983: Three ANC members charged with attacking police stations hanged.