A place of passage between the plain of Aunis, the Marais Poitevin and the sea, Usseau derives from Ussena meaning a hillock planted with vines. Attached to the canton of Mauzé-sur-le-Mignon, the commune is made up of five hamlets known locally as "les écarts": Antigny, Le Grand Breuil, Olbreuse, Le Plénisseau and Ussolière. Located at the crossroads of an ancient Roman road leading from Saintes to Nantes, the village tells the story of 2000 years of local history. Remains of several ancient sites have been revealed during the digging of trenches, gardening and ploughing. A former Huguenot centre, Usseau is the birthplace of Eléonore Desmier, born in 1639 in Olbreuse. Through marriages, her descendants are present in seventeen European dynasties, hence her nickname of grandmother of Europe. Every two years, a summer show is organised in the courtyard of her castle to honour her memory.