At the same time the barbarian conquerors maintained slavery as a matter of course, so that in the transition period slaves were perhaps more numerous than ever before (cp. Milman, _Hist. Lat. Christ._ 4th ed. ii, 45-46; Lecky, _European Morals_, ed. 1884, ii, 70). Whatever were the case in the earlier ages of barbarian irruption, it seems clear that during the Dark Ages the general tendency was to reduce "small men" in general to a servile status, whether they were of the conquering or the conquered stock. Cp. Guizot, _Essais_, as cited, pp. 161-72; _Civilisation_, iii, 172, 190-203 (leçons 7, 8). The different grades of _coloni_ and _servi_ tended to approximate to the same subjection in Europe as in the England of the twelfth century. But in France and Italy betterment seems to have set in about the eleventh century; and the famous ordinance of Louis the Fat in 1118 (given by Guizot, iii, 204) tells of a general movement, largely traceable to the Crusades, which in this connection wrought good for the tillers of the soil in the process of squandering the wealth of their masters. Cp. Duruy, _Hist. de France_, ed. 1880, i, 291. The process of causation is still somewhat obscure, and is further beclouded by _a priori_ views and prepossessions as to the part played by religion in the change. The fact that the Catholic Church everywhere, though the last to free her own slaves,[553] encouraged penitents to free theirs, is taken as a phenomenon of religion, though we have seen slavery of the worst description[554] flourishing within the past century in a devoutly Protestant community. Pope Urban II actually reduced to slavery the wives of priests who refused to submit to the law of celibacy, handing them over to the nobles or bishops.[555] The rational inference is that the motives in the medieval abandonment of slavery, as in its disuse towards the end of the Roman Empire, and as in its later re-establishments in Christian States, were economic--that (1) nobles on the one hand and burghers on the other found it to their advantage to free their slaves for military purposes,[556] by way of getting money; (2) that the Church in the Dark Ages actually had to enrol many serfs as priests, the desire of freemen to escape military service by taking orders having made necessary a prohibitory law;[557] and (3) that the Church further promoted the process,[558] especially during the crusading period, because a free laity was to her more profitable than one of slaves--as apart from her own serfs. Freemen could be made to pay clerical dues: slaves could not, save on a very small scale.