New Guinea (now part of Papua New Guinea)
British Nationality could be obtained through your birth, or through the birth of any one of your parents or grandparents, in Papua New Guinea. This arises because of Britain's relationship with Papua New Guinea and Britain's Colonial history.
To determine what form of British Nationality you might have, an analysis of your family's history must be done, and then applying it to the Nationality laws governing Papua New Guinea that have been passed over the years.
New Guinea
From 17.12.1920 until 12.12.1946, New Guinea was an Australian mandated territory in which the Crown exercised extra-territorial jurisdiction.
Between 13.12.1946 and 15.09.1975, it was an Australian Trust Territory in which the Crown exercised extra-territorial jurisdiction.
From 16.09.1975 until 30.01.1980 (after independence), it was a foreign country known as Papua New Guinea.
From 31.01.1980 until the present day, it was an independent Commonwealth country.
Papua
From 1888 until 1906, Papua was part of the Crown’s Dominions.
Thereafter, it was part of Australia until it combined with New Guinea on 15.09.1975 to form Papua New Guinea. From 16.09.1975 until 30.01.1980 (after independence), it was a foreign country known as Papua New Guinea.
From 31.01.1980 until the present day, it was an independent Commonwealth country.