Source: parikramaH on TW.
Bornu Islamic empire in Africa (N. Nigeria, Chad, Sudan, etc) didn’t have an economy of its own, but merely had a very mobile qabila militia system which prostituted itself to the Arab empires to furnish a continuous supply of captive slaves (incl women) to Mediterranean and IOR ports. Their own tribal hoi polloi furnished brainwashed mercenaries as long as the equation between Shahadat & Ghanimat was in favour of the latter.
The Bornus were always advised by Arab ulema or Arabized Sheikhs like the famous Ibn Furtu, who defined this empire always as a nemesis to its kafir neighbors, and later on a half-breed race-based hierarchy within the Ummah (best seen in the Sudan). The Bornu empire was always focused outward from the Islamic Core Master Races, as are AfPak. It’s main economy is the collection of ransom based on strategic location and nuisance value.
One could also say the same of both the slave sultans of the north & the the bahmanids in South India. The respect they accorded to the Arabic and Turkic elite was immense. They imported all manner such loungers whose imprint can still be seen. - MT