Taken as a whole, medieval monks and clerics were probably the most prolific forgers of all time. For centuries they controlled access to official documents, placing them in a perfect position to alter or forge those documents, should they so desire. And judging by the volume of their output, they evidently did so desire. What's more, their superiors could be counted on to overlook, or even approve, any textual inventions that benefitted the Church.
Papal bulls were a frequent object of forgery. In one notorious case, a count of Armagnac bribed a papal official to produce a fake papal bull allowing him to marry his sister
. Letters, church histories, lives of saints, and deeds to land were other common creations of clerical forgers.
Almost all of these forgeries went undetected for centuries until the revival of historical scholarship that began during the Renaissance. As the vast scope of the deception gradually became evident, some scholars began to wonder whether there were any medieval church documents whose authenticity could be trusted. In 1675 the Jesuit scholar Daniel van Papenbroeck published his conclusion that all ancient deeds were falsifications created by eleventh-century monks. His announcement brought the wrath of the Church down upon him, and a few years later he humbly begged forgiveness for his doubt. Another seventeenth-century scholar, Jean Hardouin
, became convinced that the majority of classical Greek and Roman literature, as well as all extant Greek and Roman coins, had actually been forged by medieval Benedictine monks.