Anti-Semitism in the history of the Jews in the Middle Ages became increasingly prevalent in the Late Middle Ages. Early instances of pogroms against Jews are recorded in the context of the First Crusade. Expulsion of Jews from cities and instances of blood libel become increasingly common in the 13th to 15th centuries. This trend peaked only after the end of the medieval period, and subsided only with Jewish emancipation in the late 18th to 19th century.
In the Middle Ages, religion played a major role in driving anti-Semitism. Though not part of Roman Catholic dogma, many Christians, including members of the clergy, have held the Jewish people collectively responsible for killing Jesus, through the so-called blood curse of Pontius Pilate in the Gospels, among other things.
As stated in the Boston College Guide to Passion Plays, "Over the course of time, Christians began to accept... that the Jewish people as a whole were responsible for killing Jesus. According to this interpretation, both the Jews present at Jesus’ death and the Jewish people collectively and for all time, have committed the sin of deicide, or God-killing. For 1900 years of Christian-Jewish history, the charge of deicide (Which was originally attributed by Melito of Sardis) has led to hatred, violence against and murder of Jews in Europe and America."
This accusation was repudiated in 1964, when the Catholic Church under Pope Paul VI issued the document Nostra aetate as a part of Vatican II.