This chapter reviews some of the ways in which Jews and Christians interacted under the Christianised Roman empire, as well as under the Sassanid empire, where both were religious minorities. Jews and Christians were competing in a direct and sometimes violent clash, while both communities claiming the same inheritance. The koinos bios of both in late antiquity is highly significant for a richer understanding of the cultural dynamics between them. Significant Jewish communities existed throughout the Christian Roman empire, whether East or West. Christian attitudes toward Jews, both public and private, apparently varied in different areas. Christian scriptures were translated into various languages, in and outside the empire. Such a web of communities went against the grain of a civic religion that could provide a unification principle for the empire. The chapter also discusses the Jewish-Christian interaction in a Christian empire, and also the developments in Palestine, where both communities lived in towns and villages.