Antisemitism Dictionary (Wikipedia) view

Antisemitism (alternatively spelled anti-semitism or anti-Semitism, also known as judophobia) is prejudice and hostility toward Jews as a religious, racial, or ethnic group. While the term's etymology indicates that antisemitism is directed against all Semitic peoples, since its creation it has been used exclusively to refer to hostility towards Jews.[1][2]

Antisemitism may be manifested in many ways, ranging from individual expressions of hatred and discrimination against individual Jews to organized violent attacks by mobs or even state police or military attacks on entire Jewish communities. Extreme instances of persecution include the German Crusade of 1096, the expulsion from England in 1290, the Spanish Inquisition, the expulsion from Spain in 1492, the expulsion from Portugal in 1497, various pogroms, and the most infamous, the Holocaust under Adolf Hitler's Nazi Germany.

Source : Wikipedia - http://en.wikipedia.org/wiki/Antisemitism