Kingdom of Kongo
The Kingdom of Kongo lasted from 1390 until 1857 when it came under the rule of the Kingdom of Portugal. The large empire spanned from the Atlantic Ocean in the West to the Kwango River in the east, and from the Congo River in the north to the Kwanza River in the south. The Kingdom consisted of several main provinces and had a sphere of influence that reached neighboring kingdoms such as Ngoyo, Kakongo, and Ndongo. The Kingdom of Kongo was largely expanded through trade, alliances, and marriages rather than through military conquest.
The capital and surrounding area were densely packed with people, much more so than the other towns and areas in the Kingdom. This allowed the King to keep manpower and supplies close so that he could centralize the state and maintain an impressive amount of power and control over the populace. In 1578 the kingdom stretched 1,685 miles and had six main provinces that each played a special role. At its height, it was the biggest state in west-central Africa.
The Mbamba province was the military stronghold and had the ability to raise a force of 400,000 trained men into battle for the service of the King. Sofala had the gold mines which was what originally drew the Portuguese to the region. The Portuguese began marrying Africans in order to curry favor and be able to move deeper into Africa. The plan worked and by the end of the 15h century, Christianity began to spread throughout the Kingdom of Kongo.
It was the Portuguese and their boundless desire for gold and slaves that would be the undoing of the kingdom. The King tried to set limits and restriction on the trade of slaves and for a while this worked to maintain a good relationship with the Portuguese. But as demand for slaves continued to grow, the population of the kingdom began to dwindle until it became nothing more than a colony to the Portuguese.