The Angolan War of Independence (; 1961–1974), called in Angola the ("Armed Struggle of National Liberation"), began as an uprising against forced cultivation of cotton, and it 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 dictatorship, and the new regime immediately stopped all military action in the African colonies, declaring its intention to grant them independence without delay. The conflict is usually approached as a branch or a theater of the wider Portuguese Overseas War, which also included the independence wars of Guinea-Bissau and of Mozambique. It was a guerrilla war in which the Portuguese army and security 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 withdrew, 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. Informally, this civil war resumed by May 1975, including street fighting in Luanda and the surrounding countryside. Background of the territory In 1482, the Kingdom of Portugal's caravels, commanded by navigator Diogo Cão, arrived in the Kingdom of Kongo. Other expeditions followed, and close relations were soon established between the two kingdoms. The Portuguese brought firearms, many other technological advances, and a new religion, Christianity. In return, the King of the Congo offered slaves, ivory and minerals. Paulo Dias de Novais founded Luanda in 1575 as . Novais occupied a strip of land with a hundred families of colonists and four hundred soldiers, and established a fortified settlement. The Portuguese crown granted Luanda the status of city in 1605. Several other settlements, forts and ports were founded and maintained by the Portuguese. Benguela, a Portuguese fort from 1587, a town from 1617, was another important early settlement founded and ruled by Portugal. The early period of Portuguese incursion was punctuated by a series of wars, treaties and disputes with local African rulers, particularly Nzinga Mbandi, who resisted Portugal with great determination. The