In order to understand the intense and multi-faceted relations between Romans and Persians during the course of late antiquity – and in particular the many military confrontations that continued into the seventh century – one has to address the overall political goals of the two great powers. These goals are therefore the starting point of the second part of our survey, in which we present and analyse the source material.

Whereas Roman generals of the Late Republic already boasted that as Alexander's successors they had extended the borders of the Roman Empire to the ends of the earth and scholars agree on Rome's claim to world domination, namely to rule an imperium sine fine (‘an empire without borders’) or ‘an empire that extended from sun rise to sun set’, there is no corresponding consensus among scholars with regard to the goals that drove Sasanian foreign policy. The following examination therefore focuses on the Sasanian claims and the ideological background of the Sasanian foreign policy vis à vis Rome. This should not, however, evoke the impression that the Sasanians acted as aggressors and the Romans as defenders of threatened possessions or territories, which, obviously, the latter had conquered in long, violent wars from an unwilling population. On the contrary, the reader should be aware that such a ‘eurocentric’ view, which has been prevalent for many decades in the scholarly literature, is not justified in any way.

Territorial claims of the Sasanians against Rome

The contemporary sources presented in this chapter indicate that immediately after ad 224 the Sasanians refused to acknowledge Rome's supremacy in the Near and Middle East.