The Eritrean War of Independence was a conflict fought between successive Ethiopian governments and Eritrean independence fighters from 1 September 1961 to 24 May 1991.

Eritrea was an Italian colony from the 1880s until the defeat of the Italians by the Allies of World War II in 1941, Eritrea then briefly became a British protectorate until 1951. The General Assembly of the United Nations held a meeting about the fate of Eritrea, in which the majority of the delegates voted for the federation of Eritrea with Ethiopia, and Eritrea became a constituent state of the Federation of Ethiopia and Eritrea in 1952. The Federation was supposed to last for ten years in which Eritreans could have mini sovereign decisions such as a parliament and some autonomy, but under the Ethiopian crown for further ones. The Assembly also assigned commissioner Anzio Mattienzo to supervise the process. Eritreans were supposed to claim Eritrea as an independent sovereign state after the ten years of federation. However, Eritrea's declining autonomy and growing discontent with Ethiopian rule caused an independence movement led by the Eritrean Liberation Front (ELF) in 1961. Hamid Idris Awate officially began the Eritrean armed struggle for independence on 1 September 1961 on the mountain of Adal, near the town of Agordat in south western Eritrea. Ethiopia annexed Eritrea the next year.Following the Ethiopian Revolution in 1974, the Derg abolished the Ethiopian Empire and established a Marxist-Leninist communist state. The Derg enjoyed support from the Soviet Union and other communist nations in fighting against the Eritreans. The ELF was supported diplomatically and militarily by various countries, particularly the People's Republic of China, which supplied the ELF with weapons and training until 1972, when Ethiopia recognized Beijing as the legitimate government of China.The Eritrean People's Liberation Front (EPLF) became the main liberation group in 1977, expelling the ELF from Eritrea, then exploiting the Ogaden War to launch a war of attrition against Ethiopia. The Ethiopian government under the Workers Party of Ethiopia lost Soviet support at the end of the 1980s and were overwhelmed by Ethiopian anti-government groups, allowing the EPLF to defeat Ethiopian forces in Eritrea in May 1991.The Ethiopian People's Revolutionary Democratic Front (EPRDF), with the help of the EPLF, defeated the People's Democratic Republic of Ethiopia (PDRE) when it took control of the capital Addis Ababa a month later. In April 1993, the Eritrean people voted almost unanimously in favour of independence in the Eritrean independence referendum, with formal international recognition of an independent, sovereign Eritrea in the same year.