The Monastic Constitutions of Lanfranc, archbishop of Canterbury between 1070 and 1089, has long been recognized as one of the most important historical sources for medieval monastic life. In this major new revision of Dom David Knowles's classic editions of 1951 and 1967, C. N. L. Brooke incorporates the historical scholarship of the last generation to offer further insight into and illumination of Lanfranc and the monastic world of the eleventh century.