In 1231, the draining of the marshes Le Marais begins. In 1240, the Knights Templar built a fortified church just outside the walls of Paris, in the northern part of the Marais. The Temple turned this district into an attractive area which became known as the Temple Quarter, and many religious institutions were built nearby: the convents des Blancs-Manteaux, de Sainte-Croix-de-la-Bretonnerie and des Carmes-Billettes, as well as the church of Sainte-Catherine-du-Val-des-Écoliers.