Early life
He is one of many sons of King Sobhuza II (who had 70 wives and at the time of his death left over 1000 grandchildren) and the only child of Ntombi Tfwala, also known as Inkhosikati LaTfwala, one of the King's younger wives. He was born at the Raleigh Fitkin Memorial Hospital, only four months before Swaziland attained independence from Britain, and after he and his mother were discharged from the hospital they went to live at one of King Sobhuza's residences of Etjeni near Masundwini Palace. His birth name was Makhosetive (King of Nations).
As a young prince, Makhosetive attended Masundwini Primary School and Lozitha Palace School. He sat for the Swaziland Primary Certificate examination in December 1982 at Phondo Royal Residence and got a First Class with merit in Mathematics and English. He developed a great interest in the royal guard, becoming the first young cadet to join the Umbutfo Swaziland Defence Force (USDF).
In September 2008, Mswati III was expected to choose his 14th wife at a ceremony of bare-breasted female virgins.
Regency
When his father died of pneumonia in 1982, the royal council Liqoqo headed by Prince Mfanasibili chose the 14-year-old prince Makhosetive to be the next king. The special council was left with the task to do this after one of King Sobhuza's last words. For the next four years two wives of the late King Sobhuza II served as regent, Queen Dzeliwe Shongwe (1982–1983) and Queen Ntombi Tfwala (1983–1986) while he continued with his education in England, attending Sherborne School before he was called back to take over.
King
He was introduced as Crown Prince in September 1983 and was crowned King on April 25, 1986, aged 18 years and 6 days, and thus making him the youngest reigning monarch. The king and his mother, whose title is Indlovukazi