In 1961, a series of uprisings exploded in Angola, Portugal’s largest colony in Africa. A struggle for the independence of all the Portuguese colonies in Africa followed, organized by the national liberation movements: the MPLA, FNLA, and UNITA in Angola, FRELIMO in Mozambique, and the PAIGC in Guinea-Bissau. The wars would end in 1974, following a military coup d'état in Lisbon and the dissolution of the Portuguese dictatorship during the Carnation Revolution. This thesis explores fourteen years of anti-colonial campaigns: the people who led the liberation movements in the Portuguese colonies, the cadres these leaders encountered in Moscow, East Berlin, Prague, Sofia, and Warsaw, and the international environment they faced. It begins by looking at contacts forged between Soviet cadres and African nationalist leaders from Portuguese colonies in the late 1950s, before offering detailed analysis of why the Soviet Union and Czechoslovakia offered assistance to the MPLA and the PAIGC in 1961, the same year Angola erupted into spasms of racial violence and the Soviet Union and the United States locked horns over the status of West Berlin. The subsequent chapters analyze the evolution of Soviet relations with the liberation movements during the 1960s and 1970s, the role this relationship played in shaping Soviet attitudes and policy in Africa, and the significance of Soviet bloc assistance in anti-colonial campaigns. This thesis also looks at the diplomacy of the liberation movements and their ideological and organizational transformations over fourteen years of guerrilla war. The final chapter evaluates the Soviet role in the decolonization of Portuguese Africa following the fall of the Portuguese dictatorship and investigates why the Soviets decided to intervene on behalf of the MPLA in the pivotal event of this thesis – the beginning of the civil war in Angola in 1975.