OP its hard to say how the persecution of the Jews started. Jews are about to celebrate Passover which marks when they where liberated from slavery in Egypt by God and lead by Moses through the parting seas. That was about 1000 years BC. Being enslaved as a people is pretty anti-semitic ! Then there are examples focusing on Jerusalem and the destruction of the first and second temples. Jews where presecuted by Christians not least as Jews do not believe Jesus to be the son of God / The Messiah. Of course subsequently there are many examples, on money lending its not against Jewish law to lend/borrow mkney wheras in Christianity / Islam its forbidden/discouraged. Of course people want to borrow money and when they can’t pay it back … you have incodents like the one in York where the Jews where burned.
O coirse critising Isreal over Palestine is not in itsef anti-semtic. Many Jews are highly critical. However, a very large number of those who champion that cause are very much anti-semtic and many people caught up in that movemnet commit anti-semitic acts or encourage others to do so. As I have posted before the Laboir party and the trade union movement have become very much involved in that.
One note from above on IS not attacking Jews. The murder of the Jews in the Belgian museum was carried out by a fighter returning from Syria, the first Paris attacks (Al-Q) included an attack on a Jewish supermarket and Coibally first tried to attack a Jewish school (when he panicked and shot the police lady). The more recent attacks which where IS inspired included the Bataclan which is a Jewish owned business and had previoulsy been subject to BDS movement protests.
Anti-semitism is very prevelent today in Europe and Jews are leaving for Israel is very high numbers. 80% of Jews now live in either the US or Israel and this percentage will only increase IMO
This recent piece is well worth watching imo
[video]http://youtu.be/Z2h7ggRUFws[/video]