The present cathedral replaces the 13th century Romanesque building. The first phase concerned the south transept and the towers, as early as 1170. The chancel was rebuilt from 1236 to 1279 by Étienne de Mortagne but the nave took much longer to build. The architect Simon du Mans rebuilt the transept and started the nave, including six spans, aisle and chapel, built during the 14th century. The first two spans correspond to those of the old Romanesque cathedral and date back to the 12th century. The nave was only finished during the 15th century by architects Jean de Dammartin, Jean Papin and Jean Durand, thanks to the generosity of Charles VII and the Duke of Brittany Jean V. The towers surrounding its entrance were erected during the first half of the 16th century. None of the architects listed in ULAN.