The abbey of Holy Trinity is, during the ducal period, one of the most prominent Norman Benedictine abbeys. This thesis studies and publishes its muniments as well as the archives of its priories up until 1190 and Raoul of Argences’ (1190-1219) appointment as abbot. The corpus of the critical edition (vol. ii), beside the annexes (vol. iii : proved forgeries, letters of administration, statistics, etc.), includes 308 entries, including 224 charters whose text has survived and 84 deperdita and legal actions that may have resulted in charters. The muniments are mainly kept at the Archives départementales de la Seine-Maritime, but the Palais Bénédictine in Fécamp keeps many charters as well, notably from the 11th century. Volume I studies their history, up to the present day, by investigating their fate during the Middle Ages and the early modern period, their partial dispersion during the French Revolution and the 19th century and, among other aspects, the acquisition of part of them by the Palais Bénédictine. The monastery’s cartularies are looked into, especially the Red Book, a late 11th or early 12th century lost cartulary, which is reconstituted in the annexes. A section is dedicated to the diplomatic of the abbots’ and the abbey’s charters : internal (common forms) and external (especially the seals) features. Another section is devoted to the forgeries, and, lastly, some case studies tackle the subject of the charters with traditional symbolic objects attached and some charters from the muniments for the abbey of Our Lady of Bernay, “daughter” of Fécamp. https://mnm.hypotheses.org/4202