sentences:  Caught between them, and attempting to play one off against the other, was Msiri, the big chief of Garanganze or Katanga, a tribal land not yet claimed by a European power, and larger than many European countries in acreage.Msiri, like many African chiefs, had started as a slave trader, and had used superior weapons obtained by trading ivory, copper and slaves, to conquer and subjugate neighbouring tribes, taking many of them as slaves for resale.By the time of the Stairs Expedition, Msiri was the unchallenged despot of the area.