Answer
Mengistu Haile Mariam was the President of the People's Democratic Republic of Ethiopia from 1974 to 1991. He was a member of the Derg, a military junta that overthrew Emperor Haile Selassie in 1974. Mengistu's rule was marked by political repression and economic mismanagement, and he was ultimately overthrown by the Ethiopian People's Revolutionary Democratic Front in 1991.