That's not true at all. There had been Jews in Europe since well before the time of the Roman Empire:
The first recorded expulsion of Jews from Rome happened in 139 BCE, which suggests they must have been a large and influential presence in pre-Emperical Rome.
There's solid evidence of a Jewish presence in the Iberian Peninsula from about the same time, and some evidence suggesting they may have been there for centuries prior to that:
https://en.wikipedia.org/wiki/History_of_the_Jews_in_Spain#Early_history_.28before_300.29 Considering how many times Iberia (Spain) changed hands from that time on, and if you're going to use time and continuity of presence to determine who is and isn't a "native", one could make a strong case that the Jewish people have more right to the title than anyone.
The arrival of Jews in the lands that would become Germany predates that of Christianity. For that matter, they were there before the arrival and settlement of at least some of the tribes that modern Germans are descended from.
http://www.jewishvirtuallibrary.org/jsource/vjw/germany.html
There's more, but I want to wait and see if you actually pay attention to any of this before I bother typing out the rest. In the meantime:
Name one.