Which European country did Angola gain independence from in 1975?

The Angolan War of Independence (1961–1974) began as an uprising against forced cotton cultivation, and became a multi-faction struggle for the control of Portugal's Overseas Province of Angola among three nationalist movements and a separatist movement. The war ended when a leftist military coup in Lisbon in April 1974 overthrew Portugal's Estado Novo regime, and the new regime immediately stopped all military action in the African colonies, declaring its intention to grant them independence without delay.

It was a guerrilla war in which the Portuguese Armed Forces waged a counter-insurgency campaign against armed groups mostly dispersed across sparsely populated areas of the vast Angolan countryside. Many atrocities were committed by all forces involved in the conflict.

In Angola, after the Portuguese had stopped the war, an armed conflict broke out among the nationalist movements. This war formally came to an end in January 1975 when the Portuguese government, the National Union for the Total Independence of Angola (UNITA), the Popular Movement for the Liberation of Angola (MPLA), and the National Liberation Front of Angola (FNLA) signed the Alvor Agreement.