The order of succession to the throne of Tonga is laid down in the 1875 constitution.
The crown descends according to male-preference cognatic primogeniture.
Only legitimate descendants through legitimate line of King George Tupou I's son and grandson, Crown Prince Tēvita ʻUnga and Prince ʻUelingatoni Ngū, are entitled to succeed.
A person loses their right of succession and deprives their descendants of their right of succession if they marries without the monarch's permission.
The current line of succession is as follows:[1]