The British Arctic Territories were a constituent region of British North America, composed of islands to the north of continental North America. They are now known as the Arctic Archipelago. The British claim to the area was based on the discoveries of Martin Frobisher (1535–1594) in the 16th century. The United Kingdom of Great Britain and Ireland passed control of the islands to Canada in 1880 by means of an imperial order in council, the Adjacent Territories Order, under the royal prerogative. That was made out of fear of the United States' interest in the area as part of the Monroe Doctrine.