When was La Sainte-Chapelle built?

While the exact dates of the start of the building are unknown a Papal Bull of Innocent IV in May 1244 implies that construction of the chapel had already begun - probably between autumn of 1241 and spring 1244. In 1246 Louis IX (St. Louis) founded a college there to assist in the celebration of worship and for the protection, organization, display and upkeep of the relics. The Chapel was formally consecrated on April 26, 1248. The site of the Chapel had been in use in late antiquity and was the palace of Philippe Auguste until it was altered and enlarged by Louis IX. Source: Centre de Monuments Nationaux, The Sainte-Chappelle, Palais de la Cite, Paris, 2001.