convenient point from which to trade with East African coastal towns. They established garrisons on the islands and built the first Zoroastrian fire temples and mosques in the southern hemisphere.
Vasco da Gama's visit in 1498 marked the beginning of European influence. In 1503 or 1504, Zanzibar became part of the Portuguese Empire when Captain Ruy Lourenço Ravasco Marques landed and demanded and received tribute from the sultan in exchange for peace. Zanzibar remained a possession of Portugal for almost two centuries. It initially became part of the Portuguese province of Arabia and Ethiopia and was administered by a governor general. Around 1571, Zanzibar became part of the western division of the Portuguese empire and was administered from Mozambique. It appears, however, that the Portuguese did not closely administer Zanzibar. The first English ship to visit Unguja, the Edward Bonaventure in 1591, found that there was no Portuguese fort or garrison. The extent of their occupation was a trade depot where produce was purchased and collected for shipment to Mozambique. "In other respects, the affairs of the island were managed by the local 'king,' the predecessor of the Mwinyi Mkuu of Dunga." This hands-off approach ended when Portugal established a fort on Pembaaround 1635 in response to the Sultan of Mombasa's slaughter of Portuguese residents several years earlier. Portugal had long considered Pemba to be a troublesome launching point for rebellions in Mombasa against Portuguese rule.
The sultans of Unguja to whom the Portuguese referred repeatedly in historical accounts probably were of African origin, with possibly some strain of Persian or Asiatic blood derived from the Persian colonists of the later Middle Ages. While the Persians left many examples of their presence on Pemba, such as ruined stone houses, the sultans of Unguja left almost no trace of their existence. Their capital at Unguja Kuu probably was an extensive native town of African
