Something of this sort seems to have followed upon the conquest by the Germanic tribes of Roman territory, and the consequent necessity of administering a more complex system than their own. As the new order took shape it showed a tendency toward more definite inheritance of rank and function than existed in the tribal society. This was due partly, no doubt, to the influence of Roman traditions, but the very nature of the civilization required it. That is, functions became more diverse and of such a character as to separate the citizens into distinct classes, the principal ones being warriors of various degrees (combining military functions with the control of land), clergy, artisans and peasants. The military and landholding class, uniting the force of arms with that of wealth, naturally dominated the others; the artisans, especially in the towns, maintained a free status which served later as the nucleus of a democratic tendency; the peasants became serfs. As the conditions did not permit organization on any free or open principle—there being little facility of travel, diffusion of knowledge or unfixed wealth—the hereditary principle naturally prevailed. Only the clergy, monopolizing most of the knowledge and communication of the time and fortified by celibacy against inheritance, maintained a comparatively open organization. It is well known that lands, and the local rule that went with them, held at first as a personal trust, gradually became a family property, and we are told that when the Emperor Conrad, in 1037, issued his edict making chiefs hereditary in Italy, he only did for the south “by a single stroke what gradual custom and policy had slowly procured for the north.”[108] Offices, armorial devices and other privileges generally followed the same course, and the servile status of serfs was also transmitted to children.