Cistercian antiphoner, which has been determined through codicological analysis to have come from the Swiss Abbey of Fille-Dieu. Later touch-ups are present, done around the 16th century, probably by the nuns or by the monks of Hautcrêt Abbey (Oron, VD), which was the mother house of Fille-Dieu until 1536. These largely darken notation or text from the earlier layer, but do not change it.
May represent an early version of the Cistercian antiphoner as dictated by the Bernardine chant reform (114); see Alicia Scarcez, Liturgie et musique [...]
Liturgie et musique à l'Abbaye cistercienne Notre-Dame de la Fille-Dieu (Romont). Histoire et catalogue des sources de sept siècles de vie chorale (Fribourg : Academic Press, 2015.)