Cap-Haïtien became the capital of the Kingdom of Northern Haiti under a king that was a former slave of what ethnicity?
Cap-Haïtien:  After the Haitian Revolution, it became the capital of the Kingdom of Northern Haiti under King Henri Christophe until 1820. Henri Christophe: Henri Christophe (] ; 6 October 1767 – 8 October 1820; used the anglicized version of Henry Christopher) was a former slave of Bambara ethnicity, and perhaps of Ibo descent, and key leader in the Haitian Revolution, which succeeded in gaining independence from France in 1804.
Bambara