In order to have any appreciation of the English monasticism of the tenth and later centuries, of its ideals, its development and its problems, it is necessary to know something of the external history and the internal evolution of the monastic institute between the death of St Benedict (c. 547) and the refoundation of Glastonbury by Dunstan almost four centuries later (c. 943). And at the outset it is essential to bear in mind the great difference that exists between the history of the monastic order previous to the rise of the Cistercians, and the history of all religious orders, monastic and others, founded since that date. In the case of the latter there have been both a single detailed code of legislation, in which changes and insertions were made at definite moments, and a clearly distinguishable body of men to whom it was applied, together with a smaller body charged with its maintenance. But in the history of the monastic order between the times of St Benedict and the times of St Bernard, and above all between the death of St Gregory the Great and the Capitularies of Aachen in 817, there is nothing of the kind. Monasticism of the most varying types existed in almost all the Christian countries of Europe before the Rule was composed, and, on the other hand, the monastery or group of monasteries for which the Rule was composed lost its corporate existence in less than half a century after the death of the Legislator.