Regula Sancti Benedicti

No book apart from the Bible was more copied in the Middle Ages than the venerable Rule of Saint Benedict, which has guided uncounted monks, nuns, oblates, and laymen to salvation for well over a millennium since it was written in the sixth century. Originating in rural Italy, its evident wisdom and simple style recommended it to Pope Saint Gregory the Great, and honoured by his approval it soon spread throughout Latin Christendom, becoming the monastic rule par excellence.