Tāufaʻāhau Tupou IV Tāufaāhau Tupou IV ( 4 July 1918 – 10 September 2006 ) , son of Queen Sālote Tupou III and her consort Prince Viliami Tungī Mailefihi , was the king of Tonga from the death of his mother in 1965 until his own death in 2006 . Biography . Marriage and children . He was married to Queen Halaevalu Mataaho Ahomee , born in 1926 , and the couple had four children : - Life and reign . The King ' s full baptismal name was Siaosi Tāufaāhau Tupoulahi , but he was soon better known by the traditional title reserved for Crown Princes : Tupoutoa , ( bestowed in 1937 ) later replaced by the title he inherited from his father : Tungī ( or using both : Tupoutoa - Tungī , in that time written as Tuboutoa - Tugi ) . He kept the Tungī title until his death . From a traditional point of view he was not only the Tungī , which is the direct descendent from the Tui Haatakalaua , but he was also , on becoming king , the 22nd Tui Kanokupolu . The link with the Tui Tonga , was more indirect . He was not a Tui Tonga too ( as that office has gone over into the Kalaniuvalu line ) , but his grandmother Lavinia Veiongo ( wife of George Tupou II ) was the great - granddaughter of Laufilitonga , the last Tui Tonga , and his wife Halaevalu Mataaho ( not to be confused with the King ' s wife of the same name and same family ) , who was the daughter of Tupou Ahomee , who was the daughter of Lātūfuipeka , the Tamahā ( sister of the Tui Tonga ) . By consequence , the King ' s daughter , Pilolevu , was the first woman in Tongan culture to really have the blood of the three major Royal dynasties in her veins and become the highest - ranking person ever . The King was a keen sportsman and religious preacher in his youth . He was educated at Newington College and studied Law at Sydney University while resident at Wesley College in Sydney , Australia . He was appointed Minister of Education by Queen Sālote in 1943 , Minister of Health in 1944 , and in 1949 , Premier . He remained a lay preacher of the Free Wesleyan Church until his death , and in some circumstances , was empowered to appoint an acting church president . In the 1970s , he was the heaviest monarch in the world , weighing in at over 200 kg ( 440 pounds or 31 stones ) . For his visits to Germany , the German Government used to commission special chairs that could support his weight . The King used to take them home , considering them as state presents . In the 1990s , he took part in a national fitness campaign , losing a third of his weight . The King was also quite tall , standing . He wielded great political authority and influence in Tonga ' s essentially aristocratic system of government , together with the country ' s nobles , who control 70 % of the Legislative Assembly of Tonga . His involvement in an investment scandal , however , involving his appointed court jester Jesse Bogdonoff , had in his last years embroiled the King in controversy , and led to calls for greater government transparency and democratisation . In 2005 , the government spent several weeks negotiating with striking civil service workers before reaching a settlement . The king ' s nephew , Tui Pelehake ( Uluvalu ) , served as mediator . A constitutional commission presented a series of recommendations for constitutional reform to the King a few weeks before his death . Death and funeral . On 15 August 2006 , Tongan Prime Minister Feleti Sevele interrupted radio and television broadcasts to announce that the King was gravely ill in the Mercy Hospital in Auckland and to ask the 104 , 000 people of the island chain to pray for their King , but he died almost a month later , at 23 : 34 on 10 September 2006 ( New Zealand time : it was just after midnight on 11 September in Tongan time ) . He was 88 and had reigned for 41 years . Tāufaāhau Tupou IV was buried on 19 September 2006 at Malae Kula ( the Royal cemetery ) in the Tongan capital , Nukualofa . Thousands of Tongans watched the funeral and mourners included many foreign dignitaries , including Japanese Crown Prince Naruhito , New Zealand Prime Minister Helen Clark , Fijian Prime Minister Laisenia Qarase , Vanuatu president Kalkot Mataskelekele , the American Samoan Governor Togiola Tulafono , Niue Premier Vivian Young , and the Duke of Gloucester , a cousin of Queen Elizabeth II . The funeral blended Christian and ancient Polynesian burial rites . The funeral was overseen by the Royal undertaker Lauaki and his men of the Haatufunga ( clan ) , also known as the " nima tapu " ( sacred hands ) . According to the " International Herald Tribune " , " Tupou IV ' s 41 - year reign made him one of the world ' s longest - serving sovereigns " , after Thailand ' s King Bhumibol Adulyadej ; Queen Elizabeth II , as queen of Australia , Barbados , Canada , Jamaica , New Zealand , and the United Kingdom , specifically ; and Samoa ' s head of state , Malietoa Tanumafili II . Honours . National Honours . He was Grand Master of the Royal Orders of Tonga :