The monastery of Montier-en-Der, on the border between Champagne and Lorraine, was one of the most important monasteries of the Middle Ages. Its cartulary, put together in the 1120s at the height of the monastery's prestige and wealth, is a crucial source of information for the history of west Francia before the twelfth century and is here published in full for the first time.Constance Brittain Bouchard begins the edition with a concise history of the monastery, codicological information on the cartulary and the other manuscripts that contain copies of charters from Montier-en-Der, and a close discussion of the polytpyque and the forged charters found within the cartulary. The Latin text of each charter is preceded by a summary of its contents, including notes identifying place names and individuals. The edition also includes a chronology for the charters, a bibliography of works on the abbey, and several maps. With information on popes, kings, and counts, on manorial structures and the obligations of peasant tenants, and on monastic reform, the cartulary will be an essential resource for the study of religious history and of the middle ages in France.