AGENAIS or AGENOIS, a former province of France. In ancient Gaul it was the country of the Nitiobroges with Aginnum for its capital, and in the 4th century it was the Civitas Agennen sium, which formed the diocese of Agen. Having in general shared the fortunes of Aquitaine during the Merovingian and Carolingian periods, Agenais next became an hereditary count ship which was purchased in 1038 by the dukes of Aquitaine. The marriage of Eleanor of Aquitaine with Henry Plantagenet in 1152 brought it under the sway of England ; but when Richard I. married his sister Joan to Raymund VI., count of Toulouse, in 1196, Agenais formed part of her dowry. With the other estates of the last independent count of Toulouse it lapsed to the Crown of France in 1271, but was restored to the king of England in 1279. During the Hundred Years' War, Agenais was frequently taken and retaken, the final retreat of the English in 1453 at last leaving the king of France in peaceable possession. Thenceforth Agenais was no more than an administrative term. At the end of the ancien regime it formed part of the "Gouvernement" of Guienne, and at the Revolution it was incorporated in the depart ment of Lot-et-Garonne, of which it constitutes nearly the whole. The title of count of Agenais was revived by the kings of France, and in 1789 was held by the family of the dukes of Richelieu.