If I can jump into being un-PC: The Jews "started it." By stripping Christians of their status as members of various synagogues, Christians were exposed to the Roman draft, which had exempted Jews. Of course, laying this fault on the Jews is desperately unfair, since the Jews could very reasonable be afraid that Christian goal of gaining converts would be taken as a deal-breaker between the Jews and the Romans: The exemption was insignificant to the Romans, and worth the price to keep the peace with the Jews who were an amazingly strong threat to the empire, having prevously been the catalyst for the destruction of the Hellenic empire. It's a totally false notion that the Jews were a small, insignificant portion of the Roman population; in fact, a long secession of emporers preceded Pilate as governors of Judea. Christianity threatened to make the numbers of the Jews overwhelming. Excluding the Christians was likely the only way of maintaining the exemption for any Jews at all.
However, once excluded, the Christians became the focus of many brutal, vicious persecutions because they refused to worship the Emperor and related Roman gods, as all soldiers were required to do.
Because of the sharp split between Christian and Jew, initiated by the Jews, by the time the gospels were in their final edits, "Jew" became not synonymous with the children of Abraham, but referred exclusively to those Jews who explicitly rejected Christ. Hence, "the Jews," as used in the gospels never included the apostles, Jesus and his family, or the throngs who came to hear Jesus preach, even though most Christians at the time they were written would have considered themselves Jewish. (Paul gives a false impression by suggesting that his people had rejected Christ. By this, he meant only the residents of the Kingdom of Judea and of Galilee; Many Hellenic Jews did become Christian.)
Nonetheless, throughout history, Christian attitudes towards Jews ranged from condescending to hostile, in clear violation of the message of Christ. No denomination in Europe is sinless in their mistreatment of Jews.
By the time of Luther, Jews were seen as resistant and contrarian outsiders living in the midst of Christians, belying the supposition that everyone would become Christian if only made aware of the benefits. As such, they were reasonably, but unjustly seen as a threat to any consensus necessary for maintaining a strong nation.
Martin Luther was born 1483 and died in 1546.
His life overlaps most of the expulsions, although the "big one" was in 1492, and he was just 11 years old.
By the time he was a young man there were few Jews around Western Europe that he could encounter.
This reminds me of the Ku Klux Klan in the Midwest in the 1920s. They were against Negroes, Catholics and Jews. For the most part there were few Negroes and fewer Jews in that part of the world ~ there were, though, plenty of Catholics. Still, your typical Ku Klux Klan member in those days reserved his invective for the Negroes and Jews.
I've often suspected that if they'd been equally noisy about the Catholics (who lived there in the millions), the Klan would have been shut down far sooner than was the ultimate case.
I see you are the moderator of the Jewish ping list. I have written as a part of this thread a very curt history of relationships between Jews and Christians... although not nearly as unfair (hopefully) as it mind seem from the first sentence, so please read more than the first sentence.
I hate to talk about people behind their backs. Especially when they are The People (hehehe...) I tried to be balanced... but not terribly hard, at all... and I was taking one side. I really am not looking to hijack this into an entire new thread, and certainly not looking to start a flame war with Jews, who I highly admire for loving God without expecting the goodies that too many of us Christians expect to get. (I probably admire the faith of conservative and Orthodox Jews more than I do of most Christians.) But I thought that some Jewish people may be better at balancing my statements that I am, so invite them to do so, if anyone feels it necessary to do so.
I promise I won't get bogged down into a back-and-forth... probably I'll be too busy saying, "sorry, that's not how I meant that" or "oooh, I shouldn't've worded it that way."