In modern scholarship, the "late" period of the Roman army begins with the accession of the Emperor Diocletian in AD 284, and ends in 480 with the death of Julius Nepos, being roughly coterminous with the Dominate. During the period 395–476, the army of the Roman Empire's western half progressively disintegrated, while its counterpart in the East, known as the East Roman army (or the early Byzantine army) remained largely intact in size and structure until the reign of Justinian I (r. AD 527–565). The Imperial Roman army of the Principate (30 BC – 284 AD) underwent a significant transformation as a result of the chaotic 3rd century. Unlike the army of the Principate, the army of the 4th century was heavily dependent on conscription and its soldiers were paid much less than in the 2nd century. Barbarians from outside the empire probably supplied a much larger proportion of the late army's recruits than in the army of the 1st and 2nd centuries, but there is little evidence that this adversely affected the army's combat performance. Scholarly estimates of the size of the 4th-century army diverge widely, ranging from ca. 400,000 to over one million effectives (i.e. from roughly the same size as the 2nd-century army to 2 or 3 times larger). This is due to fragmentary evidence, unlike the much better-documented 2nd-century army. Under the Tetrarchy, military commands were separated from administrative governorships for the first time, in contrast to the Principate, where provincial governors were also commanders-in-chief of all military forces deployed in their provinces. The main change in structure from the 2nd-century army was the establishment of large escort armies (comitatus praesentales), typically containing 20,000–30,000 top-grade palatini troops. These were normally based near the imperial capitals: (Constantinople in the East, Milan in the West), thus far from the empire's borders. These armies' primary function was to deter usurpers, and they usually campaigned under the personal command of their emperors. The legions were split into smaller units comparable in size to the auxiliary regiments of the Principate. Infantry adopted the more protective equipment of the Principate cavalry. The role of cavalry in the late army does not appear to have been greatly enhanced as compared with the army of the Principate. The evidence is that cavalry was much the same proportion of overall army numbers as in the 2nd century and that its tactical role and prestige remained