Gradually, a migration of Jews to Rome and Italy began shortly after this time. It is interesting to note that the first generation of Jewish immigrants to Rome came from the large Greek-speaking cities of the Hellenistic region. This is apparent from the inscriptions on the gravestones that have been found in the Jewish catacombs in Rome, all of which --with few exceptions-- are in Greek.
As Rome extended its control over other parts of Europe beyond the Alps and the Pyrenees, we find that Jews moved together with the Roman conquests. Evidently merchants were encouraged to follow in the train of the armies to provide the soldiers with goods that they could not get in the forests and river valleys of Gallia and Germania. In the course of time every Roman military camp, called Colonia in Latin, attracted a civilian population and cities began to rise in what were military encampments. The great German city of Köln on The Rhine, called Cologne in French and English, was originally a Roman military encampment called Colonia Agrippinensis. A Jewish community was well established in Cologne sometime before 50 B.C.E.
Well before the beginning of the Common Era there were Jewish communities established in all parts of the Roman Empire. This included the Greek cities in the eastern Mediterranean and Aegean areas, the Greek and Roman cities in all of North Africa, the Iberian Peninsula, including Spain and Lusitania (Portugal), as well as all of western Europe, including Britain. Incidentally, there is evidence that the Jews in Spain had been there for centuries before the Roman conquest. The Jewish name of Spain is Sefarad. The Jews are the only people who refer to Spain as Sefarad; everyone else calls the land Espania. And Sefarad is a very ancient designation for a part of the country which has been preserved only by its Jewish inhabitants from remote antiquity.
[Sources: Strabo, Cicero, Josephus, King Agrippa.]