This fief of the Earl of Leicester was but one of the many acquisitions by which Philip Augustus gradually bought out the feudal barons and made sure of Normandy. Other property of the Montforts, and of William the Marshal[25] are examples. And if the King allowed his burgesses their Hotel de Ville, we may be sure he destroyed the castles of the barons whenever it was possible. Even that ancient fortress of the Dukes of Normandy, called the Tour de Rouen, or the Haute Vieille Tour, he pulled down, destroying their double wall and filling up their triple moat, and erected on the "Place Bouvreuil" the new castle of the kings of France, with its six towers and the donjon keep which still exists, and is called the Tour Jeanne d'Arc. The other buildings only lasted until 1590, though a mill could be seen for almost another century which was still worked by the water that ran from the stream of Gaalor which supplied the well of the castle-keep, and was used later on for many other fountains in the city. By 1250 it had already been led through underground channels to the Rue Massacre, and by 1456 the Fountain of the Town Belfry was established which is now represented by the Fontaine de la Grosse Horloge, built in 1732. The waters themselves come originally from a spring near the foot of the Mont-aux-Malades. In his new castle Philip Augustus ordained the Echiquier de Normandie, as the supreme Tribunal of Justice in the province, whose courts were to lie alternately at Rouen, Caen, and Falaise. [Footnote 25: M. Paul Meyer, head of the Ecole des Chartes, has, I hear, just discovered a mediaeval poem about this interesting person, called the "Histoire de Guillaume le Marechal." It was in the British Museum, and his edition will be of great interest to British history.]