If any single notion about the Jews of the Graeco-Roman Diaspora commands general agreement, it is the idea that their lives centred on their synagogues.1 Especially in reconstructions of the post-70 era, Jews and their synagogues are virtually inseparable. The ancient synagogue has been studied with remarkable intensity in recent years,2 absorbing archaeologists and theologians, art historians and philologists, New Testament scholars and students of Judaism alike. There are also distinguished antecedents, among which Samuel Krauss’s acute and learned survey (1922) takes pride of place. To add another synthesis to the ever-growing literature would be scarcely useful. Nor do I propose to adjudicate between interpretations of how and why synagogues emerged, in Palestine or in the Diaspora, or how the characteristic architectural forms evolved. However, there remains, to my mind, one large and central historical question which has failed to attract the attention it deserves, and that is about the functioning of the synagogue in Jewish life. To address this, I shall engage with both broader issues and narrower linguistic considerations, in the hope of deepening our understanding of Diaspora Jewish society during the Graeco-Roman period.