In southwestern Africa, Portuguese Angola was a historical colony of the Portuguese Empire (1575–1951), the overseas province Portuguese West Africa of Estado Novo Portugal (1951–1972), and the State of Angola of the Portuguese Empire (1972–1975). The People's Republic of Angola became independent in 1975 until 1992, when the country officially changed to the "Republic of Angola" as a multi-party democratic republic. Brazil was the first country to recognize Angola's independence.

In the 16th and 17th century, Portugal ruled along the coast and engaged in military conflicts with the Kingdom of Kongo, but in the 18th century, Portugal gradually managed to colonise the interior highlands. Other polities in the region included the Kingdom of Ndongo, Kingdom of Lunda, and Mbunda Kingdom. Full control of the entire territory was not achieved until the beginning of the 20th century, when agreements with other European powers during the Scramble for Africa fixed the colony's interior borders.

The history of Portuguese presence on the territory of contemporary Angola lasted from the arrival of the explorer Diogo Cão in 1484 until the decolonization of the territory in November 1975. Over these five centuries, several different situations existed.

When in 1484, Diogo Cão and other explorers reached the Kongo Kingdom at the end of the 15th century, its present territory comprised a number of separate peoples, some organized as kingdoms or tribal federations of varying sizes. The Portuguese were interested in trade, principally in slave trade. They therefore maintained a peaceful and mutually profitable relationship with the rulers and nobles of the Kongo Kingdom. Kings such as João I and Afonso I studied Christianity and learned Portuguese, in turn Christianising their nation and sharing the benefits from the slave trade. The Portuguese established small trading posts on the lower Congo, in the area of the present Democratic Republic. A more important trading settlement on the Atlantic coast was erected at Soyo in the territory of the Kongo Kingdom. It is now Angola's northernmost town, apart from the Cabinda exclave.^{[citation needed]}

In 1575, the Portuguese established the settlement of Luanda on the coast south of the Kongo Kingdom. In the 17th century came the settlement of Benguela even farther to the south. Between 1580 and the 1820s, well over a million people from present-day Angola were exported as slaves to the New World, mainly to Brazil, but also to North America. According to Oliver and Atmore, "for 200 years, the colony of Angola developed essentially as a gigantic slave-trading enterprise". Angola was very closely linked both economically and socially to Brazil via the notorious "middle passage" of the trans-Atlantic slave trade. A mestiço (mixed race people) elite emerged in Luanda by the early 17th century whose principle source of wealth was facilitating the purchase of Africans from the interior of what is now modern Angola and the Democratic Republic of the Congo to export as slaves to Brazil. The majority of those enslaved were taken captive by their fellow Africans usually in wars and/or raids and sold to the merchants of Luanda. Portuguese sailors, explorers, soldiers and merchants had a long-standing policy of conquest and establishment of military and trading outposts in Africa with the conquest of Muslim-ruled Ceuta in 1415 and the establishment of bases in present-day Morocco and the Gulf of Guinea. The Portuguese had Catholic beliefs and their military expeditions included from the very beginning the conversion of foreign peoples.

Angola was governed in a highly militaristic style. One Portuguese author, E. Silva Correia in his 1782 book, Histdria de Angola wrote: "In no part of the Portuguese world is militia [an army] more necessary than in Angola." In 1867, the governor of Angola, Calheiros e Menezes wrote in his book Relatdrio do Governador Geral da Provincia de Angola, 1867 wrote "the normal condition of the administration of this colony is to make war, and to prepare itself for war." Most notably, every single Captain-General (renamed as Governor-General in 1836) was a serving army or naval officer. Generally, the Portuguese Army had about 2,000 European soldiers in Angola at any given moment from the 16th century into the 20th century. The Portuguese forces were backed up by the so-called guerra preta ("black war") of African troops who numbered between 5,000 to 20,000. The guerra preta were raised by loyal African sobas (chiefs) and were sometimes provided with uniforms and salaries. Service in Angola was unpopular in the Portuguese Army and it was rare for a first-rate officer to be stationed in Angola. It was only during the final campaigns of conquest between 1890 and 1920 that the officers considered to be first-rate were stationed in Angola on a regular basis, and before then Angola was widely considered to be the place where the second-rate officers unfit for promotion were sent to. Most of the Portuguese troops in Angola were degredados (criminals sent to Angola to ease the problems of prison overcrowding), deserters who likewise been sent to Angola as a punishment, and various adventurers. The rate of pay for service in Angola was the same as in Portugal, which did not inspire many to volunteer for Angola. Service in Angola was deeply unpopular as the costs of living was twice that in Portugal; the death rate from diseases was very high; many of the soldiers felt isolated out in the bush; and there were frequent complaints that the Africans did not welcome the Portuguese.

In the 17th century, conflicting economic interests led to a military confrontation with the Kongo Kingdom. Portugal defeated the Kongo Kingdom in the Battle of Mbwila on 29 October, 1665, but suffered a disastrous defeat at the Battle of Kitombo when they tried to invade Kongo in 1670. Control of most of the central highlands was achieved in the 18th century. Further reaching attempts at conquering the interior were undertaken in the 19th century. However, full Portuguese administrative control of the entire territory was not achieved until the beginning of the 20th century.

Due to the colony stretching into the interior, there was substantial admixture between Africans and Portuguese settlers, creating Afro-Portuguese communities called "Ambaquista" (or "Mbakista"), named after the town of Mbaka founded in 1618. The abolition of the trans-Atlantic slave trade in the 19th century badly damaged Angola's economy. The mestiço elite who had grown wealthy on the slave trade saw a serious fall in their social status as their principle source of income no longer existed. It was only in the 19th century with the "Scramble for Africa" that the Portuguese began to push seriously into regions in the interior of Angola that they had ignored until then, largely out of the fear that other European powers might annex the interior before Portugal did.