New Guinea (gĭnˈē) [key], island, c.342,000 sq mi (885,780 sq km), SW Pacific, N of Australia; the world's second largest island after Greenland. Politically it is divided into two sections: the Indonesian provinces of Papua and West Papua in the west and the independent country of Papua New Guinea in the east. The island is c.1,500 mi (2,410 km) long and c.400 mi (640 km) wide at the center.
Largely tropical, New Guinea has vast, rugged mountain ranges such as the Owen Stanley and the Bismarck mts., and many parts of the interior remain quite isolated even today. Jaya Peak (16,503 ft/5,030 m) in Papua is the highest point. The lower courses of the large rivers (the Fly, Sepik, Mamberamo, and Purari) are generally swampy, with a few grassy plains. The inhabitants are Melanesians, Negritos, Papuans, and Malay Indonesians. The fauna consists largely of marsupials and monotremes, with venomous snakes among the reptiles. The island is known for its many unique species of butterflies and birds of paradise. There are mangrove and sandalwood forests. Near Tembagapura are the world's largest copper mines. In addition to copper, gold, silver, and manganese are mined and oil is extracted.
New Guinea is believed to have been settled by people migrating from Southeast Asia sometime before 40,000 years ago. The island's relatively close location to Australia makes New Guinea the likely source for the ancestors of the aborigines on the neighboring continent. A complex patchwork of tribes and peoples, speaking many languages, developed over time, and local agriculture apparently arose independently of outside influence, sometime between 10,000 and 7,000 years ago.
The island was sighted by the Portuguese explorer Antonio d'Abreu in 1511 and was named for its resemblance to the Guinea coast of W Africa. During the next two centuries, the island was visited by Europeans from many nations. In 1828 the Dutch formally annexed the western half of the island, and in 1885 the British proclaimed a protectorate over the southeastern coast and the adjacent islands under the name of British New Guinea; in the same year, the Germans took possession of the northeast. Australia obtained control of British New Guinea in 1905 and renamed it the Territory of Papua.
During World War I, Australian forces occupied the German-controlled region in the northeast, which was mandated to Australia by the League of Nations in 1920. Renamed the Territory of New Guinea, this area became a UN trust territory under Australian control after World War II. The island was the scene of bitter fighting between Japanese and Allied forces. In 1949 the territories of Papua and New Guinea were merged administratively, and in 1973 they were united into a self-governing country. Full independence was gained in 1975. Netherlands New Guinea was transferred to Indonesian administration in 1963 and became a province in 1969, but there has been ongoing resistance to Indonesian rule by many Papuans. Indonesian legislation in 2001 granted Papua limited local autonomy, but national control remains strong there, and the province was subsequently divided into two.