The town, on Mont Auxois, derives it's name from Alesia, a Gallo Roman settlement and Reina a local woman who was martyred.

Alesia was the site of a siege between Caesar and the Gauls led by Versingetorix. Eventually Versingetorix surrendered to Caesar who had him killed after 6 years in captivity in Rome.

Many historians disputed that this was the site of the siege and to settle arguments, Napoleon III had excavations carried out between 1861 and 1865. These excavations at the nearby Fouilles d'Alesia proved the presence of major roman structures and relics and can be visited.