 A few windows were replaced with much lighter grisaille glass in the 14th century to improve illumination, particularly on the north side and several more were replaced with clear glass in 1753 as part of the reforms to liturgical practice that also led to the removal of the "jubé".The installation of the Vendôme Chapel between two buttresses of the nave in the early 15th century resulted in the loss of one more lancet window, though it did allow for the insertion of a fine late-gothic window with donor portraits of Louis de Bourbon and his family witnessing the Coronation of the Virgin with assorted saints.Although estimates vary (depending on how one counts compound or grouped windows) approximately 152 of the original 176 stained glass windows survive – far more than any other medieval cathedral anywhere in the world.