The Derg (officially known as the Provisional Military Government of Socialist Ethiopia) was the military junta that governed the Northeastern African country of Ethiopia from 1974 to 1987. It was established in June 1974 as the Coordinating Committee of the Armed Forces, Police and Territorial Army by low-ranking officers of the Ethiopian Army and police led by Chairman Aman Andom. The Derg was formally renamed the Provisional Military Administrative Council and in September 1974 overthrew the government of the Ethiopian Empire and Emperor Haile Selassie I during mass protests. The Derg abolished the monarchy and embraced communism as an ideology, establishing Ethiopia as a Marxist-Leninist one-party state with itself as the vanguard party in a provisional government. The abolition of feudalism, increased literacy, nationalization, and sweeping land reform including the resettlement and villagization from the Ethiopian Highlands became priorities. Mengistu Haile Mariam became Chairman in 1977, launching the Qey Shibir to eliminate political opponents, with tens of thousands imprisoned and executed without trial.
By the mid-1980s, Ethiopia was ravaged by various issues such as droughts, economic decline, the 1983–1985 famine, increasing reliance on foreign aid, mismanagement, corruption, the after-effects of failed Derg policies, the Eritrean War of Independence, and the Ethiopian Civil War between the Derg and United States-backed ethnic militias. In 1987, Mengistu abolished the Derg and formed the People's Democratic Republic of Ethiopia led by the Workers' Party of Ethiopia, with a new government dominated by surviving members of the Derg.
The brutal military dictatorship of the Derg is estimated to be responsible for the deaths of up to 2 million Ethiopians.