The Kasanje Kingdom, also known as the Jaga Kingdom, (1620–1910) was a pre-colonial Central African state. It was formed in 1620 by a mercenary band of Imbangala, which had deserted the Portuguese ranks. The state gets its name from the leader of the band, Kasanje, who settled his followers on the upper Kwango River. The Kasanje people were ruled by the Jaga, a king who was elected from among the three clans who founded the kingdom.

The Jaga or Jagas were terms applied by the Portuguese to invading bands of African warriors east and south of the kingdom of Kongo. The use of the phrase took on different connotations depending on where it was applied. There were two groups of people, both known as fierce warriors, who were dubbed jagas or the jaga. Unbeknownst to the Portuguese who encountered these warriors, the two groups were practically unrelated.

Source: https://en.wikipedia.org/wiki/Kasanje_Kingdom https://en.wikipedia.org/wiki/Jaga_(Kongo)