Flourishing Indian Ocean Trade of Swahili Coastal City-States (1070s)

Timeline

1. 1071–1074Port of Mombasa · KenyaArab and Persian merchant ships used the northeast monsoon to reach East African ports, loading ivory, gold, enslaved people, and redwood, then returned to Aden and Hormuz on the southwest monsoon; port tariffs became the city-states' main source of revenue.
2. 1075–1078Kilwa Kivinje · TanzaniaKilwa's rulers controlled the southern chain of ports, expanded stone-built warehouses and mosques, purchased gold from inland states such as the Shona, and gradually established suzerainty over several port towns of the Swahili coast.
3. 1079–1080Zanzibar · TanzaniaBantu fishermen and pastoralists intermarried and merged with Arab merchants; Swahili became the common language of trade, and Islamic law and mosque communities took root in port towns, forming an African–Asian hybrid social structure.