Largest island of the Moluccas, Indonesia. It is made up of four peninsulas enclosing three great bays; politically it includes the small islands of Ternate and Tidore. Its area is 6,865 sq mi (17,780 sq km). It is dominated by heavily wooded mountain chains, with three active volcanoes on the northern peninsula. The indigenous population, whose descendants inhabit the interior, were probably Papuan; the coastal people include many elements from surrounding islands. By the late 17th century the Dutch had obtained a foothold in Halmahera with the aid of the sultan of Ternate. With the Moluccas, it was incorporated into the Republic of Indonesia in 1949.