This work explores the role of canon law in the ecclesiastical reform movement of the eleventh century, commonly known as the Gregorian Refom movement. Focusing on the Collectio canonum of Bishop Anselm of Lucca - hitherto largely unexplored in English - it is concerned with the symbiotic relationship between canon law and reform, and seeks to explore the ways in which Anselm's writing can be seen in the context of the reformer's need to devise and articulate strategies for the renovation of the Church and Christian society. Its principal contention is that Anselm's collection cannot be seen merely as a catalogue of canon law, but also functioned to articulate, define, and propagate reformist doctrine in a time of great social and religious upheaval.