From the fifteenth century AD onwards, West Africa began to face the rigours of the Slave Trade. The challenge first came from the Portuguese. Later challenges came from other European peoples. In the region now known as Angola, there was a kingdom called Ndongo. Kabasa was its capital city. Portuguese traders exerted a great pressure on this kingdom. After 1608 their army commander-in-chief instituted a new policy of repression. Bento Cardoso devised a system whereby every Ndongo notable would be owned by a Portuguese official and was responsible for delivering a certain quantity of slaves to that official. Should the Ndongo notable fail therein, he too would be enslaved. Over a hundred notables were enslaved in a single year. In addition, the Portuguese killed a further one hundred. Even the ruler of Ndongo, himself a slave trader, resisted the aggression. War dragged on for years but the Portuguese were forced to sue for peace.
In 1622 Ann Nzinga, the Ndongo royal sister, attended a peace conference with the Portuguese convened in the coastal city of Luanda. She demanded (1) that the Portuguese evacuate Kabasa, the Ndongo capital; (2) that the Portuguese wage war on the Jaga, an African people much involved in the Slave Trade; (3) all Ndongo notables who had become vassals of the Portuguese must return to their former loyalty to the Ndongo crown. In return, Nzinga promised to hand over Portuguese prisoners of war. The provisions of the treaty were designed to end all fighting in the region, but alas the Portuguese breached it almost immediately by invading Kongo, the kingdom to the north.
In 1623 Ann Nzinga officially became the Ngola (which means King) [sic], and in this capacity made the regional alliances necessary to fight the Portuguese. She even made common cause with the Jaga. Ndongo was declared a free country the following year. All slaves entering the country were legally declared to be free. By 1629 her forces and allies captured Matamba, the neighbouring state to the east. Incidentally, this state had a tradition of being ruled by females. This too was declared a free country. The fragile alliance with the Jaga ended when their ruler betrayed her and attacked Matamba. Fortunately, dissension among the Europeans - the Dutch were encroaching on Portugal's share of the slave trade - created an opportunity for Nzinga. She established a strategic alliance with the Dutch, pitting them against the Portuguese. After the Portuguese defeated the Dutch, Nzinga retreated to the hills of Matamba, where she established a formidable resistance movement against the Portuguese. One key strategy was to get Black slave soldiers to desert to her side. She promised them land and freedom. She was the only African leader in history known to have attempted this. In 1641 Garcia II, a vigorous king, emerged in Kongo, to the north. He made alliances with the Dutch to fight Portuguese aggression. His death in 1661 ended the great era of Kongolese culture. In Ndongo, the death of Nzinga in 1663 marked a turning point. Her extraordinary and brilliant reign only delayed the inevitable.