Originally the diocese was under the metropolitan of Trier. After the French Revolution, the last prince bishop, Cardinal Louis de Montmorency-Laval (1761-1802) fled and the old organization of the diocese was broken up. With the Concordat of 1801 the diocese was re-established covering the departments of Moselle, Ardennes, and Forêts, and was put under the Archdiocese of Besançon. In 1817 the parts of the diocese which became Prussian territory were transferred to the Diocese of Trier. In 1871 the core areas of the diocese became part of Germany, and in 1874 Metz diocese, then reconfined to the borders of the new German Lorraine department became immediately subject to the Holy See. As of 1910 there were about 533,000 Catholics living in the diocese of Metz.