THE ROMAN EMPIRE 119 During the whole of this time there was only one emperor who ruled for more than thirteen years, and only two others who ruled so long. The average reign was under five years. The rulers of this series with the exception of Commodus are known as the praetorian emperors, because all were raised to the purple by the legions. Throughout this period the barbarians were be- coming more and more actively aggressive, and the emperors were more and more engaged personally on frontier warfare in- stead of in controlling the administration of the empire. Rome itself practically ceased to have any importance except of a purely sentimental character, and the Roman citizenship was extended to all the races dwelling within the empire's boundaries. The high morality and the austere religion which all tradition ascribes to the Ancient Romans who raised their city to be the first in Italy had long vanished ; nothing had taken Religion its place except the somewhat dreary austerity of and Morals, the Stoic philosophers, which appealed to a few cultivated minds. But below the surface, and mainly among the humbler ranks of society, the leaven of Christianity was spreading, strengthening and stiffening the moral fibre of large classes of the community in proportion to the courage demanded of all adherents to the faith. The next period was to witness a reaction. After one more shock of persecution, the fiercest which had ever befallen it, the Christian religion was to become suddenly dominant and fashionable ; not a faith held with a passionate conviction which craved rather than shunned the crown of martyrdom, but a creed which was professed as a matter of course ; of which the re- generative force was destroyed when it was accepted as a convention instead of a vital inspiration. Diocletian must have been endowed with an exceptionally powerful personality. After the first contest for supremacy with a son of his predecessor who died by the hand of an assassin, no rival attempted to challenge the authority of the new emperor. More than this, he could venture to associate with himself a colleague of equal authority, and subsequently two more colleagues whose powers were scarcely less, and yet while doing so he could retain a complete moral
