Had the construction of a field army on these lines proceeded in time of peace, it would necessarily have involved a reorganization of the whole system to meet the increase in expenditure. As it was, the fifty years of civil war and barbarian invasion which followed the accession of Maximin saw the old order irreparably ruined. The great Illyrian emperors who saved civilization for another century, and spent themselves in marching ceaselessly from province to province, cutting down the hydra heads of revolt and striving to repel the recurring assaults of Goth or Persian, could neither hope to maintain the old frontier lines nor spare time to collect vexillations after the second-century manner when each new danger threatened. Sweeping together Household Troops and fragments of the broken frontier armies and enlisting thousands of barbarian mercenaries, they strove to keep a concentrated force at their disposal which they moved constantly backwards and forwards across the Empire as each internal or external crisis demanded. It was this field army which shared in the imperial triumphs and received such rewards as the exhausted finances could bestow. In comparison with it such units of the old frontier troops, legions and auxilia alike, as maintained their old positions (and we shall see that many did so) sank steadily in prestige and importance. When finally the barbarian fury had temporarily spent its force, and a cessation of internal warfare granted Diocletian and Constantine breathing space in which to reorganize the civil and military administration of the Empire, the provisional reconstruction brought into being by these fifty years of stress and disaster was formally recognized and incorporated in the new order. The distinction between first and second class troops is no longer between legions and auxilia as in the days of Augustus, but between the Palatini and Comitatenses on the one hand, who followed in war the emperor himself and the new heads of the military hierarchy, the _magistri peditum_ and _equitum_, and were kept concentrated at strategic points within the Empire in time of peace, and on the other the Limitanei or Ripenses, who formed, under the _duces limitum_, a territorial frontier guard, membership in which was now hereditary in law as well as practice.[420] At this point we might legitimately take leave of our subject, for although the names of many of the old auxiliary regiments still appear in the fourth and fifth centuries among the Limitanei, there is nothing in either character or status to distinguish them from such of the old legions as had survived in a similar capacity. The title ‘auxilia’, on the other hand, is now applied to corps of new creation and barbarian origin which figure on the roll of the field army.