On February 4, 1969 the Popular Liberation Movement (MPLA) of Angola began armed struggle against the country's colonial Portuguese government. The aim was to achieve independence for Angola by means of a united front of all African interests, however, the MPLA's first leader, Mário de Andrade, an educated mestiço and a poet, gave the party a reputation for representing primarily the interests of urban intellectuals rather than the indigenous masses. The MPLA traces its Marxist-Leninist origins to its ties with the clandestine Portuguese Communist Party (Partido Comunista Português--PCP). The initial MPLA manifesto called for an end to colonialism and the building of a modern society free of prejudice, a goal that could be realized only after a lengthy period of political preparation followed by a revolutionary struggle. (adapted from: http://countrystudies.us/angola/25.htm)
I found this map of ethnic groups in Angola pretty interesting:
Also, here is a book that I found that details some of the history of colonialism in Angola. I hope to check it out soon. Let me know if you have read it and what you thought, or if you have other book/film suggestions.