British Nationality could be obtained through your birth, or through the birth of any one of your parents or grandparents, in Fiji. This arises because of Britain's relationship with Fiji and its 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 of Fiji that were passed over the years.
STATUS OF FIJI
From 1881 until 31.12.1948, Fiji (which included Rotuma) came within the Crown’s Dominions.
From 01.01.1949 until 09.10.1970, it fell within the UK and Colonies.
From 10.10.1970 until the present day, it was an independent Commonwealth country (other than a period when its membership of the Commonwealth was suspended).
Click here for more information on the status of Citizen of the United Kingdom & Colonies (CUKC), a status achieved by birth in the Colony.