Previous to his assassination on Saturday, Ali Khamenei had ranked third among the world leaders with the longest grips on power, reports Statista.

The supreme leader of Iran had been at the helm of the country since 1981, first as president and, after eight years, as Iran's de-facto head of state and religious authority. Khamenei died in U.S. and Israeli air strikes. His rule of Iran was marked by religious fervor, hostility towards other nations and brutality towards his own people, as uprisings were put down mercilessly to consolidate his power.

On the list that excludes royals, President Paul Biya of Cameroon comes first. He has headed the country for 50 years, first as prime minister between 1975 and 1982 and then as president. He built an authoritarian system in Cameroon in the 1980s and has held on to power ever since. President Teodoro Obiang Nguema Mbasogo of Equatorial Guinea comes second and has been ruling the small African country for 46 years since 1979 when he led the military junta that overthrew the country's first president after independence. The regime of the oil-rich country is employing corruption, nepotism, repression and human rights violations to stay in power.

African leaders appear frequently towards the top of the list, also including rulers from Uganda, Eritrea, the Republic of the Congo and Djibouti, which have been in office since the 1980s and 1990s. President Denis Sassou Nguesso of Congo-Brazzaville even started his first term in 1979, the same as Obiang, but was out of office for five years and returned to power in 1997 by military force. Another infamous authoritarian leader from a different part of the world, Daniel Ortega of Nicaragua, also started out in 1979 as provisional leader and 1985 as president, but spent 1990-2007 in the opposition, before returning as president and most recently co-president with his wife.

Russian President Vladimir Putin comes 10th, behind Belarus' Alexander Lukashenko in rank 7. Putin has been changing back and forth between president and prime minister for much of his tenure to avoid term limits. Including royals, the sultan of Brunei would beat the world's authoritarian leaders. Hassanal Bolkiah has been the country's absolutist leader since 1967. Figurehead Carl XVI Gustaf of Sweden has been the country's purely representative head of state since 1973, while Cameroon's Paul Biya would follow in third place.

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