The fall of the Parthian monarchy and the succession of the Sasanian dynasty mark a major turning point in the political and religious history of Iran. The nature of the Parthian monarchy certainly encouraged a degree of Jewish self-rule, and geonic sources speak in general terms of the existence of the office during the Second Temple period. In truth, only in talmudic literature does a more complete picture of this office emerge, one that draws much from a comparison of the Exilarchate with the Patriarchate of Roman Palestine. The economic life of Babylonian Jewry was not segregated from the surrounding population, and the Babylonian Talmud suggests not only the proximity of Jews and Gentiles but also a large measure of daily interaction and co-operation. Social interaction between Jews and other groups assumes a common language of discourse, and, in the case of Babylonia, that language was Babylonian Aramaic.

The Achaemenian, Arsacid and Sasanian dynasties, which together ruled Iran for more than a millennium, their coinages are an invaluable source of information about the history, culture and economic life of the Sasanian state. The alteration in Sasanian numismatic portraiture stems from Iranian national tradition; such changes reflect a rejection of the Arsacid dynasty and all it stood for a deliberate challenge to the old enemy Rome. As regards weight-standard and choice of denominations, the Sasanians at first kept strictly to existing traditions. The silver drachm of Attic weight, which even in Parthian times was everywhere the commonest currency, became the chief denomination of the Sasanian state. The formulation of Sasanian coin inscriptions is determined by the political and religious motives of the dynasty. The coin inscriptions are in Sasanian Pahlavi (Middle Persian) and, in isolated instances, ideograms are used. The problems of Sasanian numismatic art are closely connected with those of technology.

The rise of the Sasanian dynasty can be understood as the successful struggle of a minor ruler of Persis not only against his Parthian overlord, but also against a multitude of neighbouring rulers. The main adversary of the Persians was the Roman empire, and the ambitions of the first Sasanian ruler were soon countered by Rome. It was during the reign of Yazdgard that the Christians of the Sasanian empire held a council in the city of Seleucia in the year 410. Shortly after Bahrāam accession in 421 the persecution of Christians in the Sasanian empire was resumed, probably at the instigation of Zoroastrian priests. The Sasanians inherited from the Parthians a legacy of over two centuries of conflict with the western power. With a Sasanian belief in the destiny of Iran to rule over the territories once held by the Achaemenians, it was inevitable that wars between the two great powers would continue.