Its area covers the entire department of Charente-Maritime (except the very north), the west and centre of the department of Charente, the northern department of Gironde with its Pays Gabaye and its enclaves around Saintonge, Monségur; also the Aunisien (south Vendée) and Saintongeais (south Deux-Sèvres) parts of the Marais Poitevin.