(canton de Pontorson, Manche)
Church of Notre-Dame-sous-Terre
Situated below the western terrace and completely surrounded by later structures, the church of Notre-Dame-sous-Terre forms an irregular quadrilateral measuring c.12 x 9m. A central wall, which is pierced by two round-headed arches, delimits two parallel naves each ending in a flat east end with a gallery at the upper level. There is no text to help us ascertain precise dates for the construction of this church, but in the masonry we find all the characteristic features of pre-Romanesque buildings: very thick walls, built from roughly-hewn, small pieces of granite rubble laid on edge, arches bonded with flat bricks, window openings with jambs employing, alternately, rubble and brick. The building was probably built during the second half of the 10th century by Benedictine monks who established themselves at the Mount in 966.
Dom Huynes, a historian of the 17th century, indicates that he still saw in Notre-Dame-sous-Terre the altar at which St Aubert, the bishop who introduced the cult of St Michel to the Mount in 708, officiated for the first time. In 1960, when restoring the building, Yves-Marie Froidevaux unearthed a cyclopean wall which is probably a vestige of the Merovingian church built by St Aubert in 708-709. Notre-Dame-sous-Terre would thus have been built to replace the original sanctuary.
- Boüard Michel de, L'église
Notre-Dame-sous-Terre au Mont-Saint-Michel. Essai de datation. - Le Journal des
savants, 1961, p. 10-27
- Froidevaux Yves-Marie, L'église Notre-Dame-sous-Terre de l'abbaye du Mont-Saint-Michel. - Les Monuments historiques de la France, 1961, p. 145-166
- For an exhaustive bibliography, refer to the Monastic Millénaire of Mont-Saint-Michel, volume IV: bibliographie générale et sources, de Michel Nortier ; 2e éd. par Henry Decaëns. - Lethielleux, 2001