The period following the death of St. Benedict in 543 is a period of which little is known. "We repeat with Dom Baumer (vol. i., pp. 299-300) that the fifth century, at Rome as elsewhere, was a period of great liturgical activity, while the seventh and eighth centuries were, viewed from this point of view, a period of decline" (Baudot, _op. cit._, p. 53). The labours of St. Benedict probably were continued and perfected by St. Gregory the Great (590-604). His labours are summed up by Dom Baumer (_Histoire du Breviare_, vol. i., pp. 289, 301-303): "It is he who collected together the prayers and liturgical usages of his predecessors and assigned to each its proper place, and thus the liturgy owes its present form to him. The liturgical chant also bears his name, because through his means it reached its highest state of development. The canonical hours and the formulary of the Mass now in use were also carefully arranged by him." "The whole history of the Western liturgy supports us in maintaining that these books received from the great Pope or from one of his contemporaries a form which never afterwards underwent any radical or essential alteration." The Roman office spread quickly through Europe. The enthusiasm of Gregory became rooted in the monasteries, where the monks learned and taught, with knowledge and with zeal, his liturgical reforms. Two important reforms of monastic practice are interesting as showing further progress in the evolution of the Roman Breviary. St. Benedict of Aniane (751-821), the friend and adviser of Louis the Pious, became a reformer of Benedictine rule and practice. His rule aimed at a rigid uniformity, even in detail. And the Council of Aix-la-Chapelle (817) helped him to establish his reforms. As a result of the saint's exertions the Penitential Psalms and Office of the Dead were made part of the daily monastic office. The Abbey of Cluny, founded in 910, supplied a further reform tending to guard the office from further accretions.