The social state underwent a similar change. Many of the smaller feudal lords sold their fiefs, or impoverished themselves by crusading, or lost much of their power during their absence. Property and power came into fewer hands; society was more centralised, no longer dispersed as it formerly was. The citizens, on their part, were no longer content with local industry and trade; they entered upon commerce on a grander scale with countries oversea. Petty influence yielded place to larger influences; the small existences grouped themselves round the great. By the end of the Crusades, the march of society towards centralisation was in steady progress. _VI.--The Age of Centralisation_ Already, in the twelfth century, a new idea of kingship had begun, very faintly, to make its appearance. In most European countries the king, under the feudal system, had been a head who could not enforce his headship. But there was, all the while, such a thing as kingship, and somebody bore the title of king; and society, striving to escape from feudal violence and to get hold of real order and unity, had recourse to the king in an experimental way, to see, as one might say, what he could do. Gradually there developed the idea of the king as the protector of public order and justice and of the common interest as the paramount magistrate--the idea that changed Europe society from a series of classes into a group of centralised States. But the old order did not perish without efforts to perpetuate itself. These efforts were of two kinds; a particular class sought predominance, or it was proposed that the classes should agree to act in concert. To the first kind belonged the design of the Church to gain mastery over Europe that culminated with Pope Gregory VII. It failed for three reasons--because Christianity is a purely moral force and not a temporal administrative force; because the ambitions of the Church were opposed by the feudal aristocracy; and because the celibacy of the clergy prevented the formation of a caste capable of theocratic organisation. Attempts at democracy were made, for a time with apparent means, by the Italian civic republics; but they were a prey to internal disorder, their government tended to become oligarchical, and their incapacity for uniting among themselves made them the victims of foreign invaders. The Swiss Republican organisation was more successful, but became aristocratic and immobile. The House Towns and the towns of Flanders and the Rhine organised for pure defence; they preserved their privileges, but remained confined within their walls.