Junior and mid-level officers formed the Coordinating Committee of the Armed Forces, Police and Territorial Army—soon known as the Derg—during the Ethiopian Revolution, creating the nucleus of the military junta that would seize state power.
The Derg removed Emperor Haile Selassie from power in Addis Ababa, ending imperial rule and inaugurating a prolonged period of military-led revolutionary government.
Lieutenant General Aman Andom was appointed the first chairman (de facto head of state) of the Derg, reflecting the junta’s initial consolidation of authority after the September coup.
The Derg executed 60 imprisoned officials of the former imperial government at Kerchele Prison, a pivotal early escalation of revolutionary violence and political repression.
The Derg announced sweeping land reform that nationalized rural land without compensation, abolished tenancy, and restricted private agricultural labor arrangements—transforming Ethiopia’s agrarian order under a socialist program.
Following the execution of Derg chairman Tafari Benti, Mengistu Haile Mariam officially declared the Red Terror, initiating a period of mass political killings and coercion aimed at crushing civilian and armed opposition.
Somali forces launched a major invasion into Ethiopia’s Ogaden region, triggering the Ogaden War and deepening Ethiopia’s dependence on Soviet-bloc military support during the late 1970s.
Mengistu announced the creation of the Commission for Organizing the Party of the Working People of Ethiopia (COPWE), a key step toward institutionalizing one-party Marxist-Leninist rule beyond military decree.
The Derg established the Workers’ Party of Ethiopia (WPE) as the intended ruling vanguard party, replacing COPWE and preparing the political framework for a formal “people’s republic.”
After a referendum, the 1987 constitution went into effect, inaugurating the People’s Democratic Republic of Ethiopia (PDRE) and creating a formal state structure (including the National Shengo) while retaining one-party socialist rule under the WPE.
The Eritrean People’s Liberation Front (EPLF) captured the strategic Red Sea port of Massawa after fighting in February 1990, a major blow to the Ethiopian state’s war effort in Eritrea and a turning point in the late-stage conflict.
Facing rapid rebel advances and state collapse, President Mengistu Haile Mariam resigned and fled the country, ending his direct control even before the final fall of Addis Ababa.
EPRDF forces entered Addis Ababa and took key government sites, bringing the PDRE/Derg era to an end and opening a transition to a new political order after 17 years of Marxist-Leninist military-party rule.
Ethiopia — Derg and the People's Democratic Republic of Ethiopia (1974–1991)
