When referring to anti semitism, in it's most serious form, scholars deal with it from the new testament on. That is the jumping off point. Before then, yes, the Jews faced destruction and extirpation, but this was the overwhelming norm in their tribal stage of development, surrounded by other tribes with different gods and customs. Anti semitism is the specific hatred of Jews, both as an ethnicity and a religion, both working in tandem. Golden Dawn and the Church come together whenever they have a common enemy, like anti non Orthodox adoption, abortion and homosexual issues. That's enough support from both sides to safely fuck them both off.