Jannah said
Well most fled because of the rampant anti-semitism against them. I had an ex who thought my family fled Tsarist Russia due to persecution...except, as far as I know, I don't have Jewish heritage. It's also interesting to note that The Protocols of the Elders of Zion was originally published in Russian. That says a lot.
Eastern European antisemitism was always way more virulent, traditionally, than the German brand, until Hitler anyway. Hitler's antisemitism sort of popped up out of the blue, but it didn't surprise guys who checked out the philosophy of Theodor Herzl (the founder of Zionism) so much because Herzl witnessed the Dreyfuss Affair in France and theorized that antisemitism could crop up anywhere that the Jews did not have an actual homeland of their own, a nation that was theirs.
But yeah, pogroms were a thing in Eastern Europe from the middle ages on. And the Germans had a lot of help in Eastern Europe. Less in Western Europe, particularly from the Dutch, who were particularly eager to hide and shelter their Jews, and the Danish, who refused to turn over any Jews and smuggled them all out.
But, then again, before we leap to generalizations, there are more Righteous Among the Nations listed for Poland than any other nation -- that's people who actually helped Jews with no benefit to themselves and at great personal danger. Holland and France are the next largest contingents, though the Danish numbers are deceptively low -- the Danish resistance declined to be listed individually. They probably should have chiseled, "Menschen" under that entry. (Slight Yiddish joke.)
