A brief but very interesting history of the Jews in Europe which began with the conquest of the Eastern Mediterranean by none other than Pompey in 63 BCE. Thus beginning the history of Jews in the Roman Empire, though likely Alexandrian Jews had migrated to Rome slightly before Pompey's conquest of the East.
Hellenistic Judaism, originating from Alexandria, was present throughout the Roman Empire even before the Roman-Jewish Wars. As early as the middle of the 2nd century BC, the Jewish author of the third book of the Oracula Sibyllina, addressing the "chosen people," says: "Every land is full of thee and every sea." The most diverse witnesses, such as Strabo, Philo, Seneca, Cicero, and Josephus, all mention Jewish populations in the cities of the Mediterranean Basin. Most Jewish population centers of this period were however still in the East (Iudaea and Syria) and in Egypt (Alexandria was by far the most important of the Jewish communities, the Jews in Philo's time were inhabiting two of the five sections of the city). Nevertheless, at the commencement of the reign of Caesar Augustus (27BC) there were over 7,000 Jews in Rome: this is the number that escorted the envoys who came to demand the deposition of Archelaus.
The Roman Empire period presence of Jews in Croatia dates to the 2nd century, in Pannonia to the 3rd to 4th century. A finger ring with a Menorah depiction found in Augusta Raurica (Kaiseraugst, Switzerland) in 2001 attests to Jewish presence in Germania Superior. Evidence in towns north of the Loire or in southern Gaul date to the 5th century and 6th centuries.