Bourbonnais (bōōrbônā´), former province, central France, in the northern part of the Massif Central. It was approximately the same area as today's Allier dept. It is a largely arid plateau (except for the fertile Limagne area in the west). The chief cities are Moulins, Montluçon, and Vichy. Moulins, the ancient capital, has many historical monuments. The counts (later dukes) of Bourbon held the Bourbonnais as an appanage until 1527, when Francis I of France confiscated it upon the death of the constable Charles of Bourbon.