Antisemitism is the hatred and persecution of Jews. In early Western history, antisemitism was based on religious differences. Jews were subjected to abuse, massacre, and expulsion by believers in pagan gods, due to Jewish rejection of idol worship. Later, Christians persecuted Jews for not accepting Jesus of Nazareth as the Christ (the Messiah), and because of a belief that the Jews had been responsible for the death of Jesus.
During the 19th century, nationalism and race-based theories of evolution changed the basis of antisemitism from religious to racial. Jews, who accounted for a large percentage of the population of many European countries, became viewed as an alien racial group in the lands of their birth. Antisemitism based on race led to persecution, discrimination, and finally to the attempted genocide of the Jews of Europe during World War II.
