Kingdom of Gonja was a state, in northern Ghana, expanded by a ruler named Jakpa. Jakpa came from Jenne. With an armored cavalry, he invaded and conquered Gonja in 1629.
Davidson, Basil, Buah, F. K. ,and Ajayi, J.F. Ade(1966). A History of West Africa. Doubleday:New York, pp. 253,254. Library of Congress Card #66-24317