Autonomous island, formerly of Papua New Guinea, which with Buka Island and other smaller islands forms the province of North Solomon; area 10,620 sq km/4,100 sq mi; population (2011) 249,350. It is the largest of the Solomon Islands archipelago. The capital is Arawa. The land is volcanic and mountainous, with the Emperor Range in the north and Crown Prince Range in the south; the highest peak is the active volcano Mount Balbi, 3,110 m/10,205 ft. The chief industries are copper, gold, and silver; copra, ivory nuts, and tortoiseshell are exported.
The island was named after the French navigator Louis Antoine de Bougainville who arrived in 1768. It belonged to Germany from 1899 to 1914, and was assigned to Australia after World War I. It was occupied by the Japanese during World War II from March 1942 until liberated by US troops in 1943 and then held by Australia until the end of the war. In 1976 Bougainville became a province (with substantial autonomy) of Papua New Guinea. A state of emergency was declared in 1989 after secessionist violence. In 1990 the secessionist Bougainville Revolutionary Army took control of the island, declaring it independent; government troops regained control in 1992. A peace agreement in 1994 set up four neutral zones occupied by the Pacific peacekeeping force (from Fiji Islands, Tonga, and Vanuatu). In 2000 the government of Papua New Guinea sanctioned the autonomy of the island, which brought an end to years of conflict.
Environment Waste from the Paguna workings, one of the world's largest copper mines, owned by Australian company CRA Minerals, has devastated the island's environment (according to rebel government sources in 1992), silting up the streams of the Jaba River system and contaminating the water with dangerous heavy metals. In 1989, the Paguna workings produced nearly 49 million tonnes of ore and nearly 50 tonnes of waste.