Most of Swahili coast at an economic and cultural peak, though Kilwa was in decline on eve of Portuguese arrival. All the towns by this stage were Muslim, speaking an early form of Swahili, while hinterland peoples remained animist.
Portuguese built a factory on Zanzibar and established Fort Jesus and put in place a garrison of 100 men at Mombassa to secure a foothold on the Swahili coast. Elsewhere, their presence was minimal, involving only the collection of tribute.
Omani Arabs struggled with Portuguese for control of the Swahili coast. Omani raid led ruling dynasty in Zanzibar to proclaim its independence from Portuguese.
