List of Ancien Régime dioceses of France
French Ancien Régime Roman Catholic dioceses and ecclesiastical provinces were heirs of Late Roman civitates (themselves created out of Gaulish tribes) and provinces. == Historical sketch == Most of them were created during the first Christianization of Gaul, in the 3rd to 5th centuries.
Source: Wikipedia — List of Ancien Régime dioceses of France (CC BY-SA 4.0)