The South and East courtyard façades were decorated and unified with pilasters in a French Renaissance style between 1537 and 1542. Their appearance is comparable to the French Chateau of Villers-Cotterêts. The buttresses on the East are dated 1537, and on the South, where the masonry is more sophisticated, 1539. The later work may be connected with the arrival of Nicolas Roy, a French mason sent to Scotland in March 1539 by Antoinette of Bourbon, the mother of Mary of Guise. The chapel ceiling dates from the time of James V, as recent dendrochronology work by the AOC Group has confirmed, and was re-decorated for the visit of Charles I in 1633. James Murray, master of works, was ordered to repair the roof of the South Quarter in 1625, with instructions to "have a special care and regard" that the great ceiling of the Chapel be "preserved and kept as far as possibly may be."