This chapter focuses exclusively on medieval Jewish civilization, from the fall of the Roman Empire to about 1492. It includes alphabetically organized entries, written by scholars from around the world, include biographies, countries, events, social history, and religious concepts. As the capital of the Roman province Gallia Narbonensis, Narbonne was, already in antiquity, an important center of Jewish settlement in the western Mediterranean area. A prosperous community was established in the city under the Roman domination, and it was located in the center of the urban agglomeration. Jews settled in some areas of North Africa in ancient times, perhaps even in the reign of Solomon. North Africa was extremely important for Spain. On the one hand, the Muslim rulers posed a potential threat to Christian Spain. Indeed, first the Almoravids and then the Almohads had taken control of the weakened Muslim city-states in al-Andalus and proved a formidable obstacle to the Christian efforts at reconquest of the Muslim territory.