The history of this church is connected with that of the abbey which is very close by, destroyed by the French revolutionary troops in 1794. It was a place of pilgrimage for Saint Ursmer, one of the first founders of the abbey.
The building provides precious evidence of Carolingian or pre-Romanesque art. It has a plan in the shape of a Latin cross. The nave is the oldest part of the church. The vaulted crypt is impressive. It is built to a rectangular plan that reproduces that of the choir.
It contains the sarcophagus of Saint Ursmer and numerous tombstones of former abbots. The tower, dating from the 11th century, is 32m high. Its termination in a saddleback roof was completed in the 19th century.