Meet The 10 Youngest World LeadersThings to do before you're 40? Lead your country...10 images

9 San Marino has two Captains Regent, formal heads of state who hold equal power and one of them, Matteo Fiorini, is 39

8 Juri Ratas, 39 (born 2 July 1978) has been Estonian Prime Minister since November 2016

7 Leo Varadkar, Taoiseach of Ireland is 38 (born 18 January 1979), the youngest person ever to hold the post

6 Bhutan's King Jigme Khesar Namgyel Wangchuck, 37 (born 21 February 1980) came to power at the age of 26

5 Jacinda Ardern is set to become New Zealand's next Prime Minister at 37 (born 26 July 1980) less than a year after first entering parliament

4 Qatar's Emir Sheikh Tamim bin Hamad Al Thani is 37 (born 3 June 1980) and took power in 2003 when his father stepped down, despite his older brother being expected to inherit the leadership

3 Kim Jong Un, Supreme Leader of North Korea, is still only 34

2 San Marino's other Captain Regent, is even younger than his co-ruler, Enrico Carattoni, is just 32

1 But the youngest world leader is Sebastian Kurz, 31 (born 27 August 1986) newly elected as Chancellor of Austria