During the Revolution, most of the 12th century stained glass windows were destroyed in order to recover their lead. In 1799, some of them were placed in a museum. Sixteen years later, they returned to Saint-Denis in a very poor state. From 1842 to 1847, the chief architect François Debret had them restored by Alexandre Billard. Other restorations followed, carried out by Henri and Alfred Gérente. Unfortunately, some of them were broken when they were removed. With the exception of five 12th century windows, all the stained glass windows in the basilica basilica (including the northern rose) date from the 19th century.