The earliest known Tongan culture existed in the 12th century. Europeans first arrived in the 17th century. By 1900, Tonga was a British Empire Protectorate until the 1950s. It became a British commonwealth in the 1970s.
Tonga was one of the few British spheres of influence that were not overrun by the Race's Conquest Fleet during their invasion of the Earth in 1942. As the Race was not equipped to handle remote islands, Tonga never attracted their interest.