Vladimir Putin is expected to win Russia's presidential election on Sunday, giving him a fourth term that would take him to nearly a quarter-century as a head of state or government.

Other leaders who have been in power for more than a quarter of a century include Tajikistan's Emomali Rakhmon, Cameroon's Paul Biy and Equatorial Guinea's Teodoro Obiang Nguema.

Here is the list of the world rulers who have held power the longest - excluding monarchs enthroned for life.

Longest record

Cuba: Topping the list with 49 years in power is Cuba's revolutionary hero Fidel Castro, who handed over to his brother Raul in 2008 when he was in his early 80s.

Taiwan 's first president, Chiang Kai-shek, was in charge of the island and mainland China for a total of 47 years until his death in 1975.

North Korean founder Kim Il-sung ran the reclusive state for 46 years before dying in office in 1994. He is still revered as the "eternal leader".

Albania 's Enver Hoxha was in power for 40 years until his death in 1985.

Muammar Gaddafi ruled Libya with an iron fist for almost 42 years before being killed in 2011 by rebels.

Gabon: Omar Bongo Ondimba governed oil-rich Gabon for more than 41 years until his death in 2009.

Zimbabwe: Robert Mugabe rose to power in 1980, and resigned from Zimbabwe's top post in 2017, after a 37-year rule.

Still counting