POITOU, one of the old provinces of France, which also formed one of the great military governments of the kingdom, was bounded on the N. by Brittany, Anjou and Touraine, on the S. by Angoumois and Aunis; on the E. by Touraine, Berri and Marche; and on the W. by the ocean. It was divided into Lower Poitou, which corresponded to the modern department of La Vendée, and Upper Poitou, now split into the departments of Deux-Sevres and Vienne. The principal towns in Upper Poitou were Poitiers the capital, Mirebeau, Chatellerault, Richelieu, Loudun, Thouars, Mauléon, Parthenay, Niort, &c.; and in Lower Poitou Fontenay-le-Comté, Maillezais, Lucon and Roche-sur-Yon. Île d’Yeu or Île-Dieu and Noirmoutier belonged to the province. Ecclesiastically, Poitou was a diocese which was broken up in 1317 to form two new dioceses of Lucon and Maillezais, the seat of the latter was transferred in the 17th century to La Rochelle. For the administration of justice, Poitou was attached to the parlement of Paris. After 778 it formed part of the domain of the counts of Poitiers (q.v.). Poitou (Poictou, Pictavia) takes its name from the Pictones or Pictavi, a Gallic nation mentioned by Caesar, Strabo and Ptolemy, and described by Strabo as separated from the Namnetes on the north by the Loire. It formed part of the territory known as Aquitaine (q.v.).

For the history see the Mémoires of the Société des Antiquaires de l’Ouest (1835 sqq.) and the documents published by the Archives historiques du Poitou (1872 sqq.); also the Dictionnaire topographique de la Vienne, by L. Rédet (1881).