Fontenay was in existence as early as the time of the Gauls. The affix of comte is said to have been applied to it when it was taken by King Louis IX from the family of Lusignan and given to his brother Alphonse, count of Poitou, under whom it became capital of Bas-Poitou. Ceded to the Plantagenets by the Treaty of Brétigny, in 1360 it was retaken in 1372 by Duguesclin. It suffered repeated capture during the Religious Wars of the 16th century, was dismantled in 1621 and was occupied both by the Republicans and the Royalist Vendeans during the Revolt in the Vendée (1793). From 1790 to 1806 it was capital of the Vendée department.