The fall of the Derg, also known as Downfall of the Derg, was a military campaign that resulted the defeat of the ruling military junta Derg by the rebel coalition Ethiopian People's Revolutionary Democratic Front (EPRDF) on 28 May 1991 in Addis Ababa, ending the Ethiopian Civil War. The Derg took power after deposing Emperor Haile Selassie and the Solomonic dynasty, an imperial dynasty of Ethiopia that began in 1270. The Derg suffered insurgency with different factions, and separatist rebels groups since early their rule, beginning with the Ethiopian Civil War. The 1983–1985 famine, the Red Terror, and resettlement and villagization infamed the Derg with majority of Ethiopians tended to support insurgent groups like the Tigray People's Liberation Front (TPLF) and Eritrean People's Liberation Front (EPLF).
With the establishment of People's Democratic Republic of Ethiopia in 1987, the Derg government, led by Mengistu Haile Mariam, was subdued by rebel groups due to lack of support from the Soviet Union since 1990.
EPLF account
One account of the Eritrean People's Liberation Front (EPLF) written in 1980s provides little information about their struggle against the Derg regime, but not as their political ideologies. Dieter Beisel, Reise ins Land der Rebellen, Rowohlt Verlag, Hamburg, 1989, was prominent firsthand journalistic work based on the events surrounding the rebel groups.
Pre-Derg separation movement: 1958–1974
In September 1962, Eritrea was federated with Ethiopia under Emperor Haile Selassie as the ninth province of the Ethiopian Empire after being ruled as Italy's colony and then put under British administration during the Second World War in 1941. As a result, the Eritrean Liberation Movement (ELM) was formed in Sudan in 1958 to fight for independence. Haile Selassie regime became more authoritarian; political parties were persecuted and freedom of speech and press generally suppressed, and native language was banned in favor of Amharic language.
Although Eritrean resistance prevailed throughout the condition with respect to little importance, the movement regarded the turning point in formation of armed separatist groups and movement. Muslim herdsmen lowlander often cemented separatist movement while Christian in the highlands of Eritrea favored to join with Ethiopia. In July 1960, the ELM formed as the Eritrean Liberation Front (ELF) in Cairo by majority Muslims. The number of attack toward the imperial Ethiopian government went from 4 in 1962 to 27 in 1966. The ELF then grew its wing, the Eritrean Liberation Army in early 1967, forcing the Ethiopian government to deploy two brigades into three-phased counterinsurgency operation codenamed Wegaw (lit. "trash").
Early to mid-civil war: 1974–1987
The Provisional Military Administrative Committee, also known as, the Derg seized power following a coup d'état of Emperor Haile Selassie, ending the empire administration and put the country into military dictatorship regime in 1975. Upon neutralizing ELM, in mid-1960s, three factions were reorganize to establish the Eritrean People's Liberation Front (EPLF) in 1974, and its military wing Eritrean Liberation Front Army (EPLA). In 1977, the committee elected Mengistu Haile Mariam as the chairman of the Derg while disengaging military posts in Eritrea. The EPLF and ELF launched series offensive in control of most parts of Eritrea other than Asmara, Massawa, Asseb, Barentu, and Senafe. In February 1975, another insurgency group the Tigray People's Liberation Front (TPLF) was formed in response to withdrawal of these areas.
Their first attacked took place in August 1975, and the organization steadily supported by local peasants and the populace as whole. During early period of formation, the group fought with multidirectional rivalry in lieu of the central government. In 1978, the Derg commenced formal invasion of Ogaden region of Somalia, which claimed the region into integral part of Greater Somalia.
The EPLF and ELF were successful in seizing 80% of Eritrea, but the Derg as soon as diverted their attention to Eritrea after victory against Somalia, fearing the loss of Red Sea in isolation of Ethiopia. In early 1978, they organized 90,000 powerful Second Revolutionary Army (SRA) and launched multi-sided attacks against EPLF and ELF. The Derg achieved control of southern and central Eritrea since their June 1978 military operation, and resumed offensives in November 1978 to capture Agordat, Afabet and Keren.