In the long history of Jewish–Christian relations, the early Middle Ages stands as a period in which the anti-Jewish attitudes of the church fathers and councils, and the legislation of the Christian Roman Empire regarding Jews integrated into Theodosius II’s Code (438 CE), were both adopted and perpetuated. The Code recognized the legitimacy of Judaism and offered protection to Jews and their property, while at the same time subjecting them to various kinds of discrimination.

While it is true that the barbarian kings and their churches did ratify these fourth- and fifth-century laws and conciliar canons, they were often incapable of enforcing them. What is more, this period witnessed the advent of something entirely new: namely, the introduction of forced conversions by royal (Visigothic Spain) or imperial (Byzantium) decree. However, while it is certainly the case that the barbarian conquest of the West did affect the circumstances of western Jewry, Islamic victories had still greater repercussions. Around the year 600 Jews were living under Byzantine control in Greece, central Italy, Asia Minor, Syria, Palestine, North Africa, and Egypt, and those in northern Italy, Gaul, and Spain were subject to the rule of both orthodox and Arian barbarian kings. By 1100 Jews in the Near East, North Africa, Egypt, and in part of Spain were all living in lands that had been conquered by Muslims.