Emmanuel Macron, 39, who won the second round of the French presidential election on Sunday, according to estimates, will be one of the world's youngest leaders.
Here is a look at those who were still a little wet behind the ears when they attained high executive office:
Hungary: Viktor Orban became prime minister in 1998 at the age of 35. He left office in 2002 but took over again in 2010.
Belgium: Charles Michel became prime minister in 2014 at the age of 38 to become the country's youngest leader since 1840.
Estonia: Juri Ratas became prime minister in late 2016 at the age of 38.
Ukraine: Volodymyr Groysman was appointed prime minister in 2016 at the age of 38.
Greece: Alexis Tsipras was named prime minister in 2015 at the age of 40, the youngest Greek leader in 150 years.
Tunisia: Prime Minister Youssef Chahed was 40 when he took office in 2016, the youngest since Tunisian independence in 1956.
Canada: Prime Minister Justin Trudeau was 43 when he took office in 2015.
Poland: President Andrzej Duda won election in 2015 at the age of 43.
Georgia: President Giorgi Margvelashvili took the oath of office in 2013 at the age of 44.
Those no longer in power
Some young leaders have recently left or lost office:
Estonia: Taavi Roivas was just 34 years old when he became prime minister in 2014. He left office in 2016.
Kosovo: Atifete Jahjaga became president in 2011 when she was 36 years old. She left office in 2016.
Italy: Matteo Renzi ran the government from early 2014, when he was 39, until late 2016.
Britain: David Cameron was 43 when he became prime minister in 2010. He left office last year after the shock referendum to leave the EU.
Felipe Gonzalez was head of the Spanish government in 1982 at the age of 40. Tony Blair became the British premier in 1997 at the age of 43. Benazir Bhutto was Pakistan's premier in 1988 at the age of 35, and Laurent Fabius was French premier in 1984 at 37.
US president Theodore Roosevelt was 42 when he took office, and John F. Kennedy was 43.
In France, Louis Napoleon Bonaparte was previously the youngest leader, at 40 years old in 1848 and under a different political regime, followed by Valery Giscard d'Estaing, the youngest under the current system, at 48 in 1974.
Excluding democratic governments, notable young leaders at the moment include North Korea's Kim Jong-un, 34, and the emir of Qatar Sheikh Tamim bin Hamad Al-Thani, 36.
And not forgetting Moamer Kadhafi, who came to power in Libya in 1969, aged 27.