On the right the Loire receives the waters of the Furens, the Arroux, the Nivre, the Maine (formed by the Mayenne and the Sarthe with its affluent the Loir), and the Erdre, which joins the Loire at Nantes; on the left, the Allier (which receives the Dore and the Sioule), the Loiret, the Cher, the Indre, the Vienne with its affluent the Creuse, the Thouet, and the Svre-Nantaise.
Oats and barley are generally cultivated, the former more especially in the Parisian region, the latter in Mayenne and one or two of the neighboring departments.
Slate is obtained in large quantities from the departments of Maine-ct-Loire (Angers), Ardennes (Fumay) and Mayenne (Renaz).
Other groups of less importance are situated in the Lyonnais (Roanne and Tarare) and Mayenne (Laval and Mayenne).
Between these two wars William aggrandized his power at the expense of Anjou by annexing Mayenne.