The mediating rôles of the Roman provincials began with their first subjection to Roman order. For barbarians were continually brought into the provinces as slaves or prisoners of war. Next, they entered to serve as auxiliary troops, coming especially from the wavering Teutonic outskirts of the Empire. And during that time of misrule and military anarchy which came between the death of Commodus (A.D. 192) and the accession of Diocletian (A.D. 284), Teutonic inroads threatened the imperial fabric. But, apart from palpable invasions, there was a constant increase in the Teutonic inflow from the close of the second century. More and more the Teutons tilled the fields; more and more they filled the armies. They became officers of the army and officials of the Government. So long as the vigour of life and growth continued in the Latinized population of the Empire, and so long as the Roman law and order held, the assimilative power of Latin culture and Roman institutions was enormous; the barbarians became Romanized. But when self-conserving strength and coercive energy waned with Romans and provincials, when the law’s protection was no longer sure, and a dry rot infected civic institutions, then Roman civilization lost some of its transforming virtue. The barbarism of the Teutonic influx became more obstinate as the transmuting forces of civilization weakened. Evidently the decadent civilization of the Empire could no longer raise these barbarians to the level of its greater periods; it could at most impress them with such culture and such order as it still possessed. Moreover, reacting upon these disturbed and infirm conditions, barbarism put forth a positive transforming energy, tending to barbarize the Empire, its government, its army, its inhabitants. The decay of Roman institutions and the grafting of Teutonic institutions upon Roman survivals were as universal as the mingling of races, tempers, and traditions. The course of events may briefly be reviewed.