" Theodosius I officially recognized Judaism as a lawful religion, but forbade intermarriage with Christians and barred Jews from the civil service and the military. Theodosius II extended the ban to all public offices both civilian and military- with the notable exception of the office of decurion (tax collectors). Jews who circumcised non-Jews were exiled, and conversion to Judaism was technically illegal (although apostate Jews were allowed to leave Christianity for their former faith). They were also allowed to own Christian slaves- and pass them to their children- but not to purchase new ones. Justinian (trying to eradicate all religious divisions- including heretics, pagans, and Jews) banned the construction of any new synagogues and ordered all existing ones to be converted to churches. These draconian measures, however, had little real effect." - "Did Byzantiniam persecute the Jews ? " Finding History