To keep track of family ties, many ''Tongans'' make a ''Tohi'' ''Hohoko map'', a document which shows the descendants of their ancestral lines. The ancestral family is called the ''Ha`a, ''and most of us know which ''ha`a'' we are from. Chiefly titles are divided into ''ha'a'' (clan groups or lineages), with titles being "sons" or "younger brothers" to the most senior title of that ''ha'a''. The ''ha'a, ''formerly the basis of military alliances and still defining ritual obligations, gradually became less important in the 20th century.
The aristocrats (''hou'eiki'') of Tongan society trace their descent from the ''Tu'i Tonga'' or sacred ruler. Their status is assured regardless of titleholding. In the 18th century there were many titles (indicating control of land-and-people). Only a few of these titleholding chiefs were given the status of hereditary estateholder (''nopele'' or ''matapule ma'u tofi'a)'' by Tupou I ( in 1875, 1880, and 1882), by Tupou II (1894 and 1903), and by Salote Tupou III (1921). The place of residence for the Tu'i Tonga was Mu'a.
There are two other noble lines that impact Tongan genealogy. A change in government was done during the reign of Tu'i Tonga Kau'ulufonuafekai. He appointed his younger brother, Mo'ungamotu'a as the 1st Tu'i Ha'atakalaua, as a temportal king. Tu'i Tonga would remain the sacred or spiritual king while the Tu'i Ha'atakalaua would take care of running the kingdom overseeing the cultivation of plantations, and directing the people in bringing tribute to the Tu'i Tonga. Over time the Tu'i Tonga's power would wane and the Tu'i Ha'atakalaua's would grow.
Later the Tu'i Ha'atakalaua line would create another noble line known as the Tu'i Kanokupolu during the reign of the 6th Tu'i Ha'atakalaua Mo'ugatoga, who had married a Samoan chieftian named Tohuia from the island of Upolu, Samoa. Their son Ngata would receive the title and serve as the 1st Tu'i Kanakupolu [meaning the Heart of Upolu honoring his mother's island]. Ngata's personal god was known as Taliai Tupou and the name "Tupou" was adopted by many Tu'i Kanakupolu rulers and is now always affixed to the name of the reigning sovereign. Over time, the Tu'i Ha'atakalaua's power would wane during the time of Tu'i Ha'ataklaua Mulikiha'amea  and the Tu'i Kanakupolu's power would grow culminating in the union of all of Tonga [Ha'apai, Vava'u, and Tongatapu islands] under one ruler, King George Tupou I.
People moved from one village to another, so create a residental history of where your ancestors lived during their lives. Then study the history of the villages where they lived.
If you do a village family history project, all village families should be contacted and included in the project, especially the ''Nobles''. As like European overseers, Tongan ''Nobles ,''their parents and grandparents knew who were in their village and may have information to share with you about your
The further back in time, the more likely that a person has changed his or her name. If someone did something, proving themself in a certain way, they
can change their name accordingly. Study the context of the person’s life, including parents, and other family members when dealing with name changes. On some Church records, the person’s several names may be given.
Surnames were unknown in Tonga prior to the setting up of mission schools in Tonga and were not widely used until the expansion of secondary education in the late 1940s. Nowaday's most Tongans have a Tonganized papalangi name (e.g. Melenaite = Mary Knight; 'Ilaisaane = Eliza Ann; Sione = John; Tevita = David) plus a Tongan personal name (e.g. Manu, Finau,
Leo) and a surname.
Some names are not gender-specific, e.g. Tupou and Manu can be given
to both male and female.
Prior to 1943 the letter ''g'' stood for the sound ''ng'', and the Wesleyan schools used the letter ''b'' where the Catholic schools used ''p''; ''j ''had earlier been largely abandoned in favor of ''s''. In 1943 His Royal Highness Prince Tupouto's, newly appointed Minister for Education, and known to his people as His Majesty Taufa'ahau Tupou IV, approved the substitution of ''ng'' for ''g'' and promoted uniformity in the use of ''p'' and ''s'' (eliminating ''b'' and ''j'' entirely), divided words that were formerly one word, and standarized the use of the glottal stop (''fakau'a'') in written texts where the sound occurred in spoken speech.
Therefore, researchers may encounter written records that 'look' different, however, are the same person. Case study: Prior to 1943, maternal grandfather of Caroline Wolfgramm Irwin was known in government and religious records as Baula Lagi. After 1943, this same individual is known in written record as Paula [Paul] Langi. The slight difference in the sound of "P" substituting for letter "B". Other
relative' names were also subtlely changed going from Jio to Sio [Joe].