Tunisian president Beji Caid Essebsi mistakenly called French President Francois Hollande "Francois Mitterrand" during a solidarity anti-terrorist march in the capital Tunis on 29 March, according to reports.
The 88-year-old leader's slip of the tongue was met with hilarity and applause by onlookers. Essebsi quickly realised the name gaffe and exchanged a cheek kiss with a smiling Hollande.
Socialist leader Francois Mitterrand was a towering figure in French politics, serving as president from 1981 to 1995. He died in 1996.
The name gaffe occurred as thousands of Tunisians gathered to rally in solidarity against Islamist militants who killed 21 foreign tourists and a policeman in the 18 March attack on the landmark Bardo national museum in Tunis.
The march came a day after security forces killed nine members of Okba Ibn Nafaa, the Islamist militant believed to be responsible for the terrorist attack.
World leaders, including Hollande, marched under the slogan "Le Monde est Bardo" (The World is Bardo).
Italy's PM Matteo Renzi and leaders from Algeria, Belgium, Libya, Poland and the Palestinians also took part to the demonstration.
"The Tunisian people will not bow," President Beji Caid Essebsi said in a speech after the march. "We will stay united against terrorism until we wipe out this phenomenon."
"We must all fight against terrorism," Hollande told reporters. "Tunisians wanted this international solidarity."
The Bardo museum attack was the worst of its kind in the north African country after the 2011 uprising that toppled dictator Zine El-Abidine Ben Ali.
Japanese, Polish, Italian and Colombian tourists were among those killed in the attack.