This paper emphasises the significance of Syriac evidence for the history of the Jewish Diaspora, and then focuses on an episode in the Syriac Lives of the Eastern Saints by John of Ephesus, which records the demolition by the local Christians of the synagogue of a Jewish community established in a village in the territory of Amida. The significance of this story is explored in two inter-related ways. Firstly, there is the relevance of Syriac-speaking Christianity which, like Judaism, was practised on both sides of the Roman-Sasanid border. Secondly, the article suggests that the presence of Jewish communities in those areas of the Roman empire where Syriac or other dialects of Aramaic were spoken complicates the recently-proposed conception of a “split” Jewish Diaspora, of which a large part was unable to receive rabbinic writings because it knew only Greek. But for Jews living in areas where Aramaic or Syriac was spoken, there should have been no major linguistic barrier to the reception of the rabbinic learning of either Palestine or Babylonia.