Mswati was introduced as Crown Prince in September 1983 and was crowned king on 25 April 1986, aged 18 years and 6 days, and thus making him the youngest reigning monarch until the ascension of King Jigme Khesar Namgyel Wangchuck of Bhutan on 14 December 2006; he was also the youngest head of state until Joseph Kabila took office on 26 January 2001 as President of the Democratic Republic of the Congo. The king and his mother, whose title is "Indlovukati" ("Great She-Elephant"), rule jointly.