On Sept. 12, 1974, Haile Selassie was deposed, the constitution suspended, and Ethiopia proclaimed a Socialist state under a collective military dictatorship called the Provisional Military Administrative Council (PMAC), also known as the Derg. U.S. aid stopped, and Cuban and Soviet aid began. Lt. Col. Mengistu Haile Mariam became head of state in 1977. During this period Ethiopia fought against Eritrean secessionists as well as Somali rebels, and the government fought against its own people in a campaign called the “red terror.” Thousands of political opponents were killed. Mengistu remained leader until 1991, when his greatest supporter, the Soviet Union, dismantled itself. In May 2008, Ethiopia’s Supreme Court sentenced Mengistu to death in absentia. He had lived in Zimbabwe since 1991.
A group called the Ethiopian People's Revolutionary Democratic Front seized the capital in 1991, and in May a separatist guerrilla organization, the Eritrean People's Liberation Front, took control of the province of Eritrea. The two groups agreed that Eritrea would have an internationally supervised referendum on independence. This election took place in April 1993 with almost unanimous support for Eritrean independence. Ethiopia accepted and recognized Eritrea as an independent state within a few days. Sixty-eight leaders of the former military government were put on trial in April 1996 on charges that included genocide and crimes against humanity.