25 April 1986
King Mswati III (Makhosetive Dlamini), became King of Swaziland when he succeeded his late father King Sobhuza II, who had died of pneumonia in 1982. Two relatives, Queen Dzeliwe Shongwe and Queen Ntombi Thwala, served as regents until Makhosetive, who was fourteen years old when his father died, was ready to take the reigns. Queen Shongwe ruled from 1982-1983 while Queen Thwala ruled from 1983 until 1986. During that time the prospective King was pursuing his studies at the English Sherborne School.
References
Biography, King of Swaziland Mswati III Biography-'The Story of a Prince, Holding onto power, no stranger to controversy',[online], Available at: biography.jrank.org [Accessed: 24 April 2014]