Scholars have studied the history of the relationship between Rome and the Jewish people in Antiquity from many angles; however, they have focused mainly on the political and military confrontation between the two. Recently, scholarship has turned to a new research agenda less focused on conflict: the examination of the Romanness of the Jews who lived in the Roman empire, and, in particular, that of the Palestinian Rabbis. While this new trend is both welcome and necessary in order to balance previous approaches, it still leaves an essential question unanswered, perhaps the great impensé of the encounter between Jews and Romans. Beyond Roman concrete political decisions concerning Jews, and the Jews’ adoption of Roman cultural features such as baths, how did Roman imperialism affect the ways Judaism – both rabbinic and non-rabbinic – defined itself?This project shall answer this question by analyzing an overlooked dimension of the problem. It will examine how Roman imperialism challenged Judaism both religiously and politically because of the rivalry – from the Jewish perspective – between Jewish and Roman universalisms and “messianic” ideals. This analysis shall make it possible to assess how the Jewish encounter with Rome contributed to shaping Judaism itself, in particular regarding sensitive issues such as the integration of non-Jews in Jewish society, the Jews’ conception of Jewish Law as a national and/or universal law, and Israel’s role in the establishment of a just universal political order. Moreover, in order to better comprehend the specificity of the Jewish responses to Rome, this study shall compare them to those of the Greeks and other peoples dominated by Rome, as well as to those of the Christians until the beginning of the fourth century CE. Finally, it shall try to assess the impact of the Christianization of the empire on the changes within Judaism that began with its encounter with “pagan” Rome.