In September 1974, Emperor Haile Selassie was overthrown by a military coup in Ethiopia. The military committee that took power in Ethiopia is better known by its Amharic name the Derg. After the military coup the Derg broke ties with the U.S. and realigned itself with the USSR (Union of Soviet Socialist Republics) and the USSR and its eastern bloc allies replaced America as patrons of Ethiopia's aggression against Eritrea. Between January and July 1977, the ELF and EPLF armies had liberated 95% of Eritrea capturing all but 4 towns. However, in 1978–79, Ethiopia mounted a series of five massive Soviet-backed offensives and reoccupied almost all of Eritrea's major towns and cities, except for Nakfa. The EPLF withdrew to a mountain base in northern Eritrea, around the town of Nakfa. In 1980 the EPLF had offered a proposal for referendum to end the war, however, Ethiopia, thinking it had a military upper hand, rejected the offer and war continued. In February–June 1982, The EPLF managed to repulse Ethiopia's much heralded four-month "Red Star" campaign (aka the 6th offensive by Eritreans) inflicting more than 31,000 Ethiopian casualties. In 1984 the EPLF started its counter-offensive and cleared the Ethiopian from the North-eastern Sahil front. In March 1988 the EPLF demolished the Ethiopian front at Afabet in a major offensive the British Historian Basil Davidson compared to the French defeat at Dien Bien Phu. In February 1990 the EPLF liberated the strategic port of Massawa and in the process destroyed a portion of the Ethiopian Navy. A year later the war came to conclusion on May 24, 1991, when the Ethiopian army in Eritrea surrendered. Thus Eritrea's 30-year war crowned with victory.