[5] In 1524, the abbey, now entirely destitute, was turned into a secular collegiate church at the instigation of its last abbot, Rüdiger Fischer, which was then united with the Bishopric of Speyer in 1546.

The major part of the currently visible church is the work of builders under the command of abbot Edelin, in the late 13th century.

During the 14th and 15th century, the church was richly decorated with stained glass, sculptures and mural paintings but only parts of the former abundance of works survived the vandalism which occurred during the French Revolution; of the surviving stained glass, what is not seen in the church itself can be found in Strasbourg's Musée de l’Œuvre Notre-Dame.

The church contains a fresco representing Saint Christopher: with its height of 11 m (36 ft), it is the largest painted human figure on French territory.

[8] Located in the south transept of the abbey, the new organ, built by Roethinger on the principles and aesthetics of the 1950s was taken up in 1989 by Yves Koenig.