Ottoman attempts to expand their sphere of influence into the Indian Ocean failed and it was Portuguese expansion into the Indian Ocean in the early 16th century following Vasco da Gama's route of exploration that resulted in the sacking of many coastal towns by the Portuguese. Following this conflict, the Al Qasimi, a seafaring tribe based on the Northern Peninsula and Lingeh on the Iranian coast, dominated the waterways of the Southern Gulf until the arrival of British ships, which came into conflict with the incumbents.