The world's youngest leaders hail from across the globe — from democracies, monarchies, and dictatorships in Eastern and Western Europe, Asia, and the Middle East.
While seven of the eight leaders are men, the youngest — Vanessa D'Ambrosio, the 28-year-old captain regent of San Marino — is a woman.
Meet the world's eight heads of state under 40:
View As: One Page Slides

8. Volodymyr Groysman, 39, is Ukraine's youngest ever prime minister. He was elected by Parliament in April 2016 and is a close ally of the president, Petro Poroshenko, who took power in 2014 following the ousting of the Russian-backed authoritarian Viktor Yanukovych.
Reuters

7. Jüri Ratas, 38, is the new prime minister of Estonia (he was voted into office in November 2016) and the leader of the country's Centre Party.
Ints Kalnins/Reuters

6. Saleh Ali al-Sammad, 38, is the leader of the Houthi militants, who control much of Yemen, including the capital, Sanaa. (The US is providing support to the Saudi-led coalition fighting the Houthis, and Yemen also has a separate provisional government with a president and prime minister.)
Khaled Abdullah/Reuters

5. Macedonian Prime Minister Emil Dimitriev, 38, took power in January 2016 after his predecessor, Nikola Gruevski, agreed to step down following protests against Gruevski for alleged mass wiretapping of Macedonian officials.
Boris Grdanoski/AP

4. Jigme Khesar Namgyel Wangchuck, 37, is the fifth king of Bhutan — a position he took on when he was just 26 and his father abdicated the throne. Wangchuck oversaw the institution of the country's new constitution in 2008, and is encouraging democratization.
Triston Yeo/Getty Images

3. Sheikh Tamim bin Hamad Al Thani, 36, is the Emir of Qatar — a post he took over in 2013 from his father (who took power from his own father in a non-violent coup 18 years prior).
Carl Court/Getty Images

2. Kim Jong-un, who succeeded his father as supreme leader of North Korea in 2011, is just 33. He has continued to brutally repress opposition within the closed-off country and escalate testing of its nuclear missiles.
North Korean leader Kim Jong Un is hugged by children during his visit to Samjiyon County in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang.

1. At 28, Vanessa D'Ambrosio, who is serving a six-month term as the captain regent of San Marino, a mountainous European microstate, is the youngest leader of any country in the world. D'Ambrosio will lead the country alongside her co-captain regent, Mimma Zavoli, until October 2017.
Twitter/Vanessa D'Ambrosio

Here in Nigeria we continue to be led by a certificateless old man way passed 80 years

And Buhari is 74 ( Political age for that matter)