Whether these first private castles were provided with towers we have no evidence either to prove or to disprove. No instance occurs from which we can conclude that they possessed any kind of citadel, before the middle of the 10th century.[177] But before the century is far advanced, we hear of towers in connection with the great towns, which, whether they were originally mural towers or not, are evidently private strongholds, and may justly be called keeps. The earliest instance known to the writer is in 924, when the tower of the _presidium_ where Herbert Count of Vermandois had imprisoned Charles the Simple was burnt accidentally.[178] This tower must have been restored, as nine years later it withstood a six weeks' siege from King Raoul. A possibly earlier instance is that of Nantes, where Bishop Fulcher had made a castle in 889; for when this castle was restored by Count Alan Barbetorte (937-943), we are told that he _restored_ the principal tower and made it into his own house.[179] Count Herbert built a keep in Laon before 931; and this appears to have been a different tower to the one attached to the royal house which Louis d'Outremer had built at the gate of the city.[180] We hear also of towers at Amiens (950), Coucy (958), Chalons (963), and Rheims (988). All these towers, it will be observed, are connected with towns.[181] The first stone keep in the country for whose date we have positive evidence, is that of Langeais, built by Fulk Nerra, Count of Anjou, about the year 994; its ruins still exist.