Of the collegiate church founded in 1082 by count Robert who wished to make Mortain a political and religious capital of the southern borders of Normandy, all that remains is a very fine portal in the south wing of the church. Even this was probably just a late embellishment (c. 1140).
- Baylé, Maylis. " Mortain, collégiale
Saint-Evroult " in L'Architecture normande au Moyen-Age, t. 2. Edit.
Corlet et Presses Universitaires de Caen, 1997
- Erlande-Brandenburg, Alain. " Mortain, collégiale Saint-Evroul " in Dictionnaire des Eglises de France, IVB Normandie, Robert Laffont, 1968