collected traces of the original polychrome paint from the columns, and in 1842 presented a comprehensive plan for interior decoration. In the soubassements, the lower portions where no traces of original color were found, they used a neutral tone, to avoid conflicting with the colors of the stained glass windows. For their palette of colors on other decoration, they drew upon the illuminations of a 13th-century book of Psalm from the Royal Library. They systematically repainted the forty-four 13th-century quadrilobe medallions on the stone arches of the soubassements, which depicted the martyrdom of saints presented against a gilded background. In 1845 Steinheil continued by repainting all of the medallions of the nave, with the exception of those in the two royal alcoves, following the original compositions. In 1983 the Service of Historic Monuments cleaned four of the medallions which had not been restored, and un-restored two which had been repainted, to study the original traces of paint from before 1845. The relics and the reliquary The principal relics for which the chapel was built were the crown of thorns, believed to have been worn by Christ during his Passion, and a small piece of the cross on which he was crucified. These were found Constantinople, which had been captured by the Crusaders in 1204, and was then ruled by Baudouin II of Cortenay. Baudouin agreed to sell the crown for 135,000 livres, which went primarily to Venetian bankers, to whom he had mortgaged the crown to pay for the defence of the city. By purchasing the crown, Louis gained the prestige of funding the conquest of Constantinople, as well as displaying his personal devotion. The crown arrived in August 1239 and was placed in the earlier royal chapel of St. Nicholas, near the palace. Two years later, he made an additional purchase from Baudouin of a piece of the true cross and other relics related to the Passion, which were brought to Paris in September 1241. Thereafter, on each Holy Friday, the day of the Crucifixion, he conducted a solemn ceremony at Sainte-Chapelle, in which the relic was brought out and displayed to the faithful. The King had a large Chasse, or reliquary, made to hold and display the sacred objects. This was a case, open on the front, long, made of silver and gilded copper. Each of the individual objects had its own case of precious metal with jewels.