Much of Eastern Arabia was controlled by the Usfurids in 1253, but control of the region was seized by the prince of Ormus in 1320. Qatar's pearls provided the kingdom with one of its main sources of income. In 1515, Manuel I of Portugal vassalised the Kingdom of Ormus. Portugal went on to seize a significant portion of Eastern Arabia in 1521. In 1550, the inhabitants of Al-Hasa voluntarily submitted to the rule of the Ottomans, preferring them to the Portuguese. Having retained a negligible military presence in the area, the Ottomans were expelled by the Bani Khalid tribe in 1670.