The remarkable growth of monasticism brought great wealth and political power, which were used in large measure to strengthen the Church. Kings and nobles made large grants of lands--especially Charles the Great and Louis the Pious. Besides many monks brought their possessions as gifts to the monastery and not infrequently powerful abbots took lands by force. Monasticism thus gradually became secularised and also feudalised. Monasteries were often used as prisons for deposed kings, criminals, and clergy convicted of crime. The abbots were virtually secular lords who ruled as local sovereigns, claimed immunity from tolls and taxes, went hunting and hawking, and even fought at the head of their troops. As a result the office of abbot became a coveted prize, for the younger and the illegitimate sons of nobles.[217:1] What effect this secularisation had upon the high ideals may be easily seen. Soon only certain ceremonies distinguished the monks from the secular clergy. The monks as such belong to the laity. Monasticism was viewed as a lay institution as late as the Council of Chalcedon (451)[217:2] when the legal authority of the bishop over the monks of his diocese was recognised. The monks were called _religiosi_ in contrast to the _seculares_, the priests. The monks were the "regulars" who formed the spiritual nobility and not the ruling class in the hierarchy. They formed another grade in the hierarchy between the clergy and the laity. But after the fifth century the difference became less marked. Since monasticism was considered the perfection of Christian life, it was natural to choose the clergy from the monks. Gregory the Great was the first monk to be elected Pope. Monasteries were the theological seminaries to supply priests for the Church, hence the ignorant clergy looked up to the educated monks. Still monks at first, because not ordained, could not say mass nor hear confession. Each monastery kept a priest or an ordained monk to fulfil these duties. Abbots were usually in priestly orders.[218:1] In time, however, monks assumed the dress of priests and became ambitious for priestly powers,[218:2] especially after the Council of Chalcedon, backed by the state, gave bishops jurisdiction over cloisters. Often monasteries applied to the Pope for independence from episcopal jurisdiction and were taken under the immediate protection of the Bishop of Rome. By the sixth century monks were classed in the popular mind with the clergy. In 827 a council at Rome ordered that abbots should be in priests' orders. Monks now began to sit in and to control Church synods, and to exercise all the rights of the secular clergy, even to having parishes,[218:3] and thus became powerful rivals of the established priesthood.