The chain of city-states along East Africa's Indian Ocean shore — Kilwa, Mombasa, Lamu, Zanzibar — that built a trading civilization from monsoon winds, gold, and Islamic-African urban culture, before the Portuguese arrived with cannon and broke the system open.
On a small island off the coast of present-day Tanzania, medieval traders built a palace from coral stone and sea-lime. It had vaulted ceilings, a bathhouse, and porcelain from China stacked in its walls as decoration. This was Kilwa — the city a 14th-century Moroccan traveler called one of the most beautiful in the world. It sat not on a great river, not near a fertile plain, but on a dot of coral rock in the Indian Ocean. Its wealth came entirely from the sea, from the monsoon winds, and from a web of trade that reached from the African interior to the palaces of Arabia and the harbors of India. Almost no one in the West has heard of it.