Guinea-Bissau is a republic located on the west coast of Africa. The country is bounded by Senegal in the north, and by Guinea in the east and south, with access to the Atlantic Ocean in the west. Earliest recorded history of the region dates back to the kingdom of Gabu, which formed part of the Mali Empire. The area was explored by the Portuguese and claimed by Nuno Tristão in 1446, with trading posts established on the coast and rivers over a period of two centuries. The British attempted unsuccessfully to colonize the offshore island of Bolama in 1790. It was named Portuguese Guinea and declared a colony in 1879, with the formal borders recognized by a convention with France in 1886. In 1951 it became an overseas province of Portugal and declared independence in 1973. The capital and major port is Bissau. Estimated population of Guinea-Bissau in 2010 was 1,647,000.