Answer
Mengistu Haile Mariam was the dictator of Ethiopia from 1974 to 1991. He was overthrown in 1991 by the Ethiopian People's Revolutionary Democratic Front (EPRDF). The EPRDF was a coalition of rebel groups that had been fighting against Mengistu's government for many years. After Mengistu's departure, the EPRDF established a new government and the Ethiopian Civil War came to an end.