Outline of main combatants
Angola's three rebel movements had their roots in the anti-colonial movements of the 1950s. The MPLA was primarily an urban based movement in Luanda and its surrounding area. It was largely composed of Mbundu people. By contrast the other two major anti-colonial movements the FNLA and UNITA, were rurally based groups. The FNLA largely consisted of Bakongo people hailing from Northern Angola. UNITA, an offshoot of the FNLA, was mainly composed of Ovimbundu people from the Central highlands.
Since its formation in the 1950s, the MPLA's main social base has been among the Ambundu people and the multiracial intelligentsia of cities such as Luanda, Benguela and Huambo. During its anti-colonial struggle of 1962–74, the MPLA was supported by several African countries, as well as by the Soviet Union. Cuba became the MPLA's strongest ally, sending significant contingents of combat and support personnel to Angola. This support, as well as that of several other countries of the Eastern Bloc, e.g. Romania and East Germany, was maintained during the Civil War. Yugoslavia provided financial military support for the MPLA, including $14 million in 1977, as well as Yugoslav security personnel in the country and diplomatic training for Angolans in Belgrade. The United States Ambassador to Yugoslavia wrote of the Yugoslav relationship with the MPLA, and remarked, "Tito clearly enjoys his role as patriarch of guerrilla liberation struggle." Agostinho Neto, MPLA's leader during the civil war, declared in 1977 that Yugoslav aid was constant and firm, and described the help as extraordinary. According to a November, 1978 special communique, Portuguese troops were among the 20,000 MPLA troops that participated in a major offensive in central and southern Angola.
The FNLA formed parallel to the MPLA, and was initially devoted to defending the interests of the Bakongo people and supporting the restoration of the historical Kongo Empire. However, it rapidly developed into a nationalist movement, supported in its struggle against Portugal by the government of Mobutu Sese Seko in Zaire. During the early 1960s, the FNLA was also supported by the People's Republic of China, but when UNITA was founded in the mid-1960s, China switched its support to this new movement, because the FNLA had shown little real activity. The United States refused to give the FNLA support during the movement's war against Portugal, which was a NATO ally of the U.S.; however, the FNLA did receive U.S. aid during the civil war.
UNITA's main social basis were the Ovimbundu of central Angola, who constituted about one third of the country's population, but the organization also had roots among several less numerous peoples of eastern Angola. UNITA was founded in 1966 by Jonas Savimbi, who until then had been a prominent leader of the FNLA. During the anti-colonial war, UNITA received some support from the People's Republic of China. With the onset of the civil war, the United States decided to support UNITA and considerably augmented their aid to UNITA in the decades that followed. However, in the latter period, UNITA's main ally was the Republic of South Africa.