What is the name of the Gothic royal chapel in Paris built by Louis IX?

The Gothic royal chapel in Paris built by Louis IX is Sainte-Chapelle.

Louis IX commissioned Sainte-Chapelle within the Palais de la Cité on Île de la Cité. Construction took place in the 1240s, and the chapel was consecrated on 26 April 1248. Its primary purpose was to house Louis’s collection of Passion relics, especially the Crown of Thorns and a fragment of the True Cross.

The chapel is built on two levels. The lower chapel served people connected with the royal palace, while the upper chapel was reserved for the king, his household, and prestigious ceremonies. The upper level is famous for its exceptionally tall stained-glass windows, which turn much of the wall surface into vivid biblical imagery.

The name is often confused with “Saint-Chapelle,” but Sainte-Chapelle is the established French name. It is also distinct from Notre-Dame, the cathedral on the same island, and from the Basilica of Saint-Denis, the traditional royal necropolis. Sainte-Chapelle is regarded as one of the masterpieces of Rayonnant Gothic.