A country consisting of the eastern half of the island of New Guinea and adjacent islands, including New Britain, New ireland, the Admiralty islands, and New Hanover in the Bismarck Archipelago; Bougainville and Buka in the northern Solomon islands; the D'Entrecasteaux and Trobriand islands; Woodlark (Murua) Island; and the Louisiade Archipelago. It became independent on September 16, 1975. Formerly, the southern part was the Australian Territory of Papua, and the northern part was the UN trust Territory of New Guinea, administered by australia. They were administratively merged in 1949 and named Papua and New Guinea, and renamed papua new guinea in 1971.