began. It was first conducted by Félix Duban, then by Jean-Baptiste Lassus and Émile Boeswillwald, with the young Eugène Viollet-le-Duc as an assistant. The work continued for twenty-eight years, and served as a training ground for a generation of archeologists and restorers. It was faithful to the original drawings and descriptions of the chapel that survived. The restoration of the stained glass was a parallel project, which lasted from 1846 until 1855, with the goal of returning the chapel to its original appearance. It was carried out by the glass craftsmen Antoine Lusson and Maréchal de Metz and the designer Louis Steinheil. About one third of the glass, added in later years, was removed and replaced with medieval glass from other sources, or with new glass made in the original Gothic style. Eighteen of the original panels are found today in the Musée de Cluny in Paris. The stained glass was removed and placed into safe storage during World War II. In 1945 a layer of external varnish had been applied to protect the glass from the dust and scratches of wartime bombing. This had gradually darkened, making the already fading images even harder to see. In 2008, a more comprehensive seven-year programme of restoration began, costing some €10 million to clean and preserve all the stained glass, clean the facade stonework and conserve and repair some of the sculptures. Half of the funding was provided by private donors, the other half coming from the Villum Foundation. Included in the restoration was an innovative thermoformed glass layer applied outside the stained-glass windows for added protection. The restoration of the flamboyant rose window on the west facade was completed in 2015 in time for the 800th anniversary of the birth of St. Louis. Timeline 1239 - Louis IX purchases the reputed Crown of Thorns 1241 - The crown and other relics arrive in Paris 1242-44 - Construction begins 1248 – Sainte-Chapelle completed and consecrated 1264-1267 - Installation of the tribune of relics 1383 - First spire rebuilt End of 15th c. - Monumental exterior stairway built by Louis XII 1460 (approx.) 14th century spire replaced 1485-1498 - west rose window installed 1630 - Fire damages spire and outer stairway 1690 - Flood damages lower chapel - original lower chapel stained glass removed 1793 - Revolutionaries smash portals and royal emblems. Chapel turned to civil use, and spire destroyed. 1803-1837 - Chapel