Construction began sometime after 1238 and the chapel was consecrated on 26 April 1248. The Sainte-Chapelle is considered among the highest achievements of the Rayonnant period of Gothic architecture. It was commissioned by King Louis IX of France to house his collection of Passion relics, including Christ's Crown of Thorns – one of the most important relics in medieval Christendom, later hosted in the nearby Notre-Dame Cathedral until the 2019 fire, which it survived.