In 1516 a local chieftain in Gujarat, Sultan Mahmud Begda, constructed the fort on the island, strategically located at the mouth of the Vaitarna river. In the 1530s the Portuguese had established their operations in the coastal area, headquartered at Fort Bassein, and soon gained control of the island. The Portuguese captain of Bassein donated the island to a Portuguese nobleman who tore down the old fort and began construction of a fort. The nobleman never completed the fort. Still, it remained under Portuguese control for two centuries; they used it to control shipping and navigation along the northern Konkan coast.