St. Eusebius, Bishop of Vercelli, was the first Western prelate who associated monastic and clerical life. His clergy passed their existence in fasting, praying, reading, and labour. St. Ambrosius says, “These clergy only changed their condition for a bishopric or martyrdom.” At about the same period (352–360) St. Martin founded, in the neighbourhood of Poitiers, the most ancient of the monasteries in Gaul (_Monasterium Locociagense_), and twelve years afterwards, the famous Abbey of Marmoutiers, which was so rich a nursery of holy prelates and learned doctors. The sermons of St. Basilius, in the kingdom of Pontus, his numerous monastic foundations, the rules which he laid down, and which were forthwith adopted by all the Eastern monks, bear witness to the strength of the Christian movement in Asia towards the close of the fourth century. [Illustration: Fig. 237.--St. Jerome in the desert: the saint is holding in his hand a stone with which he is about to beat his beast.--From a picture of the School of Andrea del Sarto (Sixteenth Century), in the Louvre.] The great monastery of Tabennæ, which at that time served as the type for all conventual foundations, comprised a vast network of small houses, built one after the other, and united under the supreme control of one head. The religious administration of the monastery was, moreover, entrusted to a prior or abbot, who was assisted by a deputy, while the steward who was entrusted with the secular duties--the daily expenditure, and the incidents connected with material life--also had an assistant, who took his place when he was absent. The monastery was thus divided into _houses_, each managed by a prior; each house contained a certain number of chambers, or cells, and each cell was always shared by three monks. It required three or four houses to constitute the _tribe_, or monastery.