As more pilgrims came to the Mont Saint Michel, it was decided to expand the abbey by building a new abbey church at the site of the monks' quarters, which was moved to the north of Notre-Dame-Sous-Terre.
The new church-abbey first had three crypts built: the Trente-Cierges chapel (under the North wing), the choir crypt (to the East) and Saint-Martin chapel (under the South wing) (1031-1047).