Different theories exist regarding the emergence of the Gothic style. One of these relates to the mysticism of light combined with the ambition of the master builders to replace the stone walls of churches with those made of colored glass. Attempts to achieve this can already be found among Romanesque structures.

In the upper church of Sainte-Chapelle in Paris, however, this dream came true with fifteen large glass windows and a rose window. More than half of the stained glass is still medieval.

King Louis IX, the saint, had this High Gothic building, with its simple exterior, built in the middle of the thirteenth century as a shrine for important relics, such as the crown of thorns. He had bought these from Baldwin II, the ruler of the Latin Empire, which after the conquest of Constantinople by Crusaders and Venetians in the Fourth Crusade essentially consisted only of the city.
Translation: Erik Eising