The Territory of Papua and New Guinea was established by an administrative union between the Australian-administered territories of Papua and New Guinea .
Shortly after the start of the Pacific War, the island of New Guinea was invaded by the Japanese. Most of West Papua, at that time known as Dutch New Guinea, was occupied, as were large parts of the Territory of New Guinea. Following the Surrender of Japan in 1945, civil administration of Papua and New Guinea was restored and in 1949 Papua and New Guinea were combined in an administrative union as the Territory of Papua and New Guinea.
In 1972, the name of the Territory changed to “Papua New Guinea” and in 1975 it became the Independent State of Papua New Guinea.