Foreigners at Home: The Historical Geography and Demography of the Jews of Ancient Rome Samuele Rocca Abstract In this paper, I discuss the demographic evolution and geographical location of the Jewish communities in Rome from the Late Republic, when there is clear evidence of a Jewish settlement, till the eve of the barbarian invasions in Late An- tiquity. I focus on two main topics, frst the historical geography of the Jews living in ancient Rome, or where they lived, and the demographic development of the Jewish community, or how many Jews lived in the urbs. It seems that it is possible to trace the evolution of the areas of Jewish settlement in ancient Rome by using literary as well as archaeological sources. Thus, while during the Late Republic most of the Jews probably lived in the Subura, by the Augustan period the newly developed Transtiberinum neighborhood (Regio XIV) had become the main area of settlement, as with most of the other foreign immigrants who either dwelled there individually or in groups. By the end of Late Antiquity, the Jewish commu- nities were scattered also in the southernmost area of Rome (Regio I), as well as in the eastern part of the city (Regio VI). In many cases, Jewish communities lived in the same areas as Christian groups, often concentrated around tituli. Otherwise, the number of the Jews living in Rome fuctuated through the ages and was never stable in ways that were consistent with the fuctuation of the general population of the city of Rome. Yet, literary sources (like Josephus for earlier periods) and data coming from a close analysis of the catacombs make it clear that the Jewish population of Rome was always quite small, probably no more than 1% of the en- tire population and oscillating from 10,000 in the frst half of the second century C.E. to no more than 6,000 at the close of the fourth century C.E. Keywords: Jewish Community, Rome (city), Regiones (Rome), Jewish Catacombs, Collegia, Ossilegium, Columbaria.