The Bougainville campaign was a series of land and naval battles of the Pacific campaign of World War II between Allied forces and the Empire of Japan, named after the island of Bougainville. It was part of Operation Cartwheel, the Allied grand strategy in the South Pacific. The campaign took place in the Northern Solomons in two phases. The first phase, in which American troops landed and held the perimeter around the beachhead at Torokina, lasted from November 1943 through November 1944.