This chapter traces the gradual unwinding of the Notitia system in response to the shifting strategic needs of the east Roman empire. Anastasius began the process by deploying the praesental armies to the east, first against the Isaurians and then against the Persians, but it was Justinian who fully dismantled them. Beginning with his creation of a new military command for Armenia and continuing through the establishment of a standing field army for North Africa and Italy, Justinain cannibalized the praesental armies and dispersed the striking power of the armies of Oriens, Thrace, and Illyricum. The consequences of Justinian’s decisions were keenly felt by his successors who struggled to defend the empire against escalating threats in the Balkans and the east. By the time Herakleios came to the throne, the Romans could barely muster three field armies, those for Thrace, Armenia, and Oriens, and it was these depleted armies that Herakleios used to defeat Persia and lay the basis for the thematic armies of Byzantium.

After thirty years of Ostrogothic rule in Italy (493–534) that ended with the ensuing destruction of the Gothic War (535–54), the eastern emperor Justinian sought to reassert direct control over Italy. The sixth-century Wars of Procopius vividly describes three sieges and two sacks of Rome during the course of this war. But the focus of this chapter is rather on Roman recovery in the aftermath of the war. I emphasize the constitutions in an underappreciated document from this period, Justianian’s Pragmatic Sanction. These enactments, along with texts and material evidence, show how damaging the Justinianic reconstruction of Italy was to Rome and senatorial aristocratic society. In this vacuum, the popes of Rome took on an ever-greater secular role, as the letters of Pope Pelagius show.