Sainte Chapelle is a royal chapel built within a former royal palace, the Palais de la Cité. It was built over 7 years from 1238 during the reign of King Louis IX.
It was designed to house the kings collection of Passion relics which included Christ's crown of thorns. Famous as a fine example of Gothic architecture, it contains probably the most extensive collection of 13th century stained glass in the world.