Ancient and medieval literature has bequeathed to us dialogues between Jews and Christians. Though there can be no doubt that polemical exchanges existed between individuals in the context of private discussions or formal debates, the exact relation of the dialogical texts and historical reality is sometimes unclear. In the case of ancient Christian dialogues, contradicting analyses have been put forward. Some scholars think they represent reliable documents about the real debates. Others contend that such texts are purely literary entities, and that their purpose was self-definition. Certainly no general theory can be adduced to account for all early Christian dialogical texts against the Jews. The present book, however, tries to evaluate both views with a series of contributions on a neglected late antique Greek dialogue, the Dialogue of Timothy and Aquila (6th-7th c. AD). For the sake of comparison, the second part includes papers on a medieval latin dialogical text, the Dialogus written by Peter Alfonsi (11th-12th c. AD). The last part gathers studies about the less documented other side: Jewish polemical texts against Christianity. The book is introduced by a historiographical survey by William Horbury.