Interesting. So, are you saying the Romans and Byzantines forced complete circumcision on the Jews?
No, not at all, unless you mean in a very roundabout way. The Romans and the Byzantines didn't want the Jews to circumcise themselves, period. It was the Jewish rabbis that advocated complete circumcision so that men would no longer be able to pass as uncircumcised. Back around the time of Christ, many Hellenized Jews actually even used weights to stretch the foreskin a bit, to all but completely erase the appearance of circumcision (which wasn't that hard for them, since there wasn't much cut away). That's what the rabbis and other Jewish community leaders wanted to put an end to. It was a way of preserving the community in the face of persecution.
But it was definitely not imposed by the Romans, except in the sense that it was a response to Roman persecution.