Joe Biden became the oldest president in US history when he took office in 2021, aged 78. He would be 82 at his second inauguration and 86 by the time he left office — almost a decade older than the previous record-holder, Ronald Reagan, who finished his second term at 77.
Doctors declared Mr Biden, who does not drink alcohol and exercises five times a week, "fit for duty" after an examination in February. The White House says his record shows that he is mentally sharp enough for the rigours of the job.
Mr Biden is among a handful of world leaders who continue to serve into their old age, many of them in Africa.
Cameroonian 'Sphinx'
The world's oldest elected leader is Cameroon's president Paul Biya, 90, who has ruled with an iron fist for more than four decades.
Ronald Reagan was still in the White House and the Soviet Union nearly a decade away from collapse when Mr Biya took the helm of the west African country in 1982.
Nicknamed "the Sphinx" for his inscrutable nature, he won a seventh consecutive term in October 2018 after elections marred by allegations of fraud.
Cameroon's President Paul Biya is the world's oldest elected leader. Source: Getty / Ludovic Marin
African elders
The world's youngest continent has long been dominated by elderly strongmen. Here are three other leaders in their 80s:
Zimbabwean President Emmerson Mnangagwa: the 80-year-old nicknamed "The Crocodile" for his ruthlessness, has ruled the roost since the overthrow of his former mentor Robert Mugabe in 2017.
Namibian President Hage Geingob, 81: a political veteran in power since 2014, he secured a second five-year term in 2019 on the back of enduring support for his SWAPO party, which led Namibia to independence from South Africa in 1990.
Ivory Coast President Alassane Ouattara: the French-backed 81-year-old has been in power since 2011, when he ousted his arch-rival Laurent Gbagbo whose refusal to accept electoral defeat sparked months of violence.
Source: SBS News
Palestinian leader Abbas
Mahmoud Abbas, who has been head of the Palestinian Authority since 2005 after five decades in Yasser Arafat's shadow, is one of the world's oldest elected leaders at the age of 88.
A tireless advocate of a negotiated two-state solution to the Israeli-Palestinian conflict, he has enjoyed strong backing from the international community.
But polls in recent years have showed most Palestinians are wanting him to step aside.
Mahmoud Abbas, 88, has been the head of the Palestinian Authority since 2005, after spending five decades under Yasser Arafat's leadership. Source: Getty / Contributor
Ireland, Italy and Malta
Three European presidents with mainly ceremonial powers are in their eighties:
Irish politician-poet Michael Higgins, 82, has served as president of Ireland since November 2011.
Popular for his everyman approach (he queues for cash himself at the ATM) and devotion to the arts, he was comfortably re-elected in 2018.
US President Joe Biden (R) reacts alongside Irish President Michael D Higgins after signing the visitors book at the Irish President's official residence Áras an Uachtaráin on 13 April, 2023 in Dublin, Ireland. Source: Getty / Charles McQuillan
The former constitutional court judge only wanted to be president once but finally agreed to stay on for a second term in 2022 after parliament, which elects the head of state, failed to agree on his successor.
Malta's 81-year-old George Vella is a former foreign minister, doctor and anti-abortion campaigner, who became president in 2019 on a promise to fight for "the respect for life from start to finish of every individual."
