You misunderstand me. I'm not saying it pre-dated Hitler--though anti-semitism sure did--but the Holocaust proper, the exterminsation of the Jews started only after Poland fell into Hitler's grasp. Tom was right about Hitler expelling the Jews. That's what he wanted at first. The Nazis basically stole all Jew wealth before allowing them to leave the brutal climate, and when other countries didn't want to take them Hitler took this as proof everyone hated Jews as much as he did. Rooselvt even had to turn away a ship full of Jews that no other country would take and they ended up in a concentration camp.
As Hitler expanded, first Austria then Poland, the anti-semitism grew more murderous and led to murder camps.