Tonga is made up of three main groups of islands extending over 500 miles in the South Pacific; from south to north: Tongatapu, Ha'apai and Vava'u. Following an abortive mission by the London Missionary Society in 1797, the first WM missionary, Walter Lawry, arrived in 1822, but was ordered to return to Australia a year later because of local hostility and little encouragement or support from the WMMS. In 1826 John Thomas, accompanied by John Hutchinson from Australia, launched a more permanent mission. They were joined in 1827 by Nathaniel Turner and William Cross, in 1831 by Peter Turner, James Watkin and William Woon and in 1834 by David Cargill.
A break-through occurred in 1830 when King Taufa'ahau of Ha'apai, was converted and baptized . He became a local preacher and, as King George Tupou I (from 1845) played a key part in the mission. The royal family remained Methodist after his death. Finau, king of Vava'u, was also converted, but more significant was the revival which spread through the islands in 1834, nourished especially by the ministry of Peter Turner. One significant result was the decision to extend the Tongan mission to Fijiand Samoa. James E. Moulton's service (from 1865 almost to his death in 1909) was marked by the founding in 1866 of Tupou College, intended for the provision of a superior education.
Long-established dissension, centred on Shirley W. Baker while Moulton was absent in England 1878-80, resulted in the formation of the breakaway Free Wesleyan Church. Some of those loyal to Moulton and the WMMS faced persecution. Reconciliation (and then only partial) was not achieved until 1924, largely through the efforts of Queen Salote Tupou III, who reigned from 1918 to 1965 and whose visit to England at the time of the Coronation of Queen Elizabeth II was so memorable. Her son and successor, King Taufa'ahau Tupou IV, who died in 2006, was, like her, the world's only Methodist monarch. Tongan Methodism maintained its Australian links until 1977, becoming fully autonomous at the time of the formation of the Uniting Church of Australia. In 1997 it reported a membership of 32,869 and a community roll of 70,000.