[7] Birthright nationality applies to: Regular naturalisation in Tonga is acquired by application solely at the discretion of the monarch.

[9][10] Applicants must provide evidence that they are of good character; have familiarity with the Tongan language; intend to live there, and have resided within the territory for five years.

[24] Working with English Methodist missionaries, Tupou established a governance system based upon the British model to insure that Western Powers would recognise the legitimacy of Tongan sovereignty.

[21] In 1839 and 1850, Tupou promulgated written legal codes to establish courts and criminal law and define family relationships, chiefly authority, land use, and religious observances.

[24] In 1875, the first constitution was promulgated, which named but did not define native-born subjects and established that foreigners could naturalise.

[24] To appease security concerns of Australia and New Zealand, in 1879 a Treaty of Friendship was entered into with Britain and in 1886, Tonga signed a similar agreement with the United States.

[33] The law did not allow Tongan women who married foreign men to pass their nationality to their husbands.

[12][33] In 1970, Tonga ceased to be a British Protected State and joined the Commonwealth of Nations as an independent monarchy.

[35] Two years later, the Nationality Act was amended granting the King the authority to naturalise persons on humanitarian grounds, but the provision was repealed in 1988.

The changes included the ability of either native-born Tongan parent to pass on their nationality to their child born in Tonga or abroad.