Portugal fought a long and bitter counter-insurgency conflict in its three primary African colonies—Angola, Mozambique, and Guinea-Bissau—from the 1960s to the mid-1970s, when they finally received independence following the Carnation Revolution. In Mozambique, the armed struggle against colonial rule was spearheaded by the Front for the Liberation of Mozambique (FRELIMO), which was initially formed in exile but later succeeded in wresting control of large sections of the country from the Portuguese. FRELIMO drew its initial base of support primarily from Mozambican migrant workers and expatriate intellectuals who had been exposed to the emerging popularity of anti-colonial and nationalist causes overseas, as well as the Makonde and other ethnic groups in northern Mozambique, where Portuguese influence was weakest. The bulk of its members were drawn from Makonde workers who had witnessed pro-independence rallies in British-ruled Tanganyika. In September 1964, FRELIMO commenced an armed insurgency against the Portuguese. Its decision to take up arms was influenced by a number of internal and external factors, namely the recent successes of indigenous anti-colonial guerrilla movements in French Indochina and French Algeria, as well as encouragement from contemporary African statesmen such as Ahmed Ben Bella, Gamal Abdel Nasser, and Julius Nyerere. FRELIMO guerrillas initially received training primarily in North Africa and the Middle East in countries such as Algeria, with the Soviet Union and People's Republic of China providing military equipment.