In the 18th century the central kingdom, Kandy, was the only surviving independent state on the island of Ceylon. The Dutch, who had obtained their first coastal possessions in 1636, had driven out the Portuguese to become the dominant power in the island. In 1796 the British East India Company sent a naval force to Ceylon (as the British then called it). The Dutch surrendered their possessions, which left the British in control of the maritime areas surrounding Kandy. These areas were at first attached to the Madras Presidency of India but in 1802 they were constituted a separate colony under the Crown. Once the British began to develop their new territory they came to see Kandy as a threat. The Kandyan Convention of 1815 annexed Kandy to British Ceylon while recognizing most of the traditional rights of the chiefs. However, in 1817 the chiefs rebelled. The rebellion was suppressed and the rights established by the Convention were abolished.