In 1267 the cathedral's southwest tower fell; it may have been one built in Carolingian times from the proceeds of a gold retable, or it may have been a XII-century tower of Archbishop Hugues de Toucy's time, as are the two lower stories of the present northwest tower. Its fall necessitated the remaking of the last two bays of the nave and of the damaged western doors during the early XIV century. The side chapels were built then, too, but they have been rehandled in the present day, and are now dissimulated behind an arcaded wall. A record of 1319 speaks of the able Nicholas de Chaumes as architect here before he proceeded to Meaux Cathedral. He demolished the ancient chapel on the transept's southern arm, but its corresponding chapel, on the transept's northern arm, still exists and is, with the ambulatory walls, the oldest part of the church. Not till after the Hundred Years' War, however, was the plan to erect a new transept carried through. Sens then possessed as its archbishop, during forty years, the energetic Tristan de Salazar (d. 1519) who had fought, sword in hand, with Louis XII in the Italian wars. Like Bishop Jacques d'Amboise, who was then finishing at Paris the present Musée Cluny as town house for his abbey of Cluny, Archbishop de Salazar built the Hôtel Sens in Paris for his diocesan house. To his own cathedral he added the southwest tower's upper story (to which later a Renaissance lantern was attached) and he connected the synodal hall with the episcopal palace by a rich gallery. Some sculptured panels now attached to a pier in the nave of Sens Cathedral originally formed part of a tomb he had made for his parents. It was this munificent art patron who began the late-Gothic transept. In 1490 the most notable architect of the day, Martin Chambiges, was invited to direct the work, and for four years he gave it his personal supervision until called to Troyes to make the Flamboyant Gothic façade of that cathedral.