This question was tackled by fearless Professor Israel Yuval of Hebrew University in Jerusalem in his seminal [7] book , available in Hebrew. Its English translation was supposed to appear a few years ago in California University Press, but for variety of reasons this has not happened yet. It is certainly sheer coincidence that some American Jewish scholars objected to this book being published and called to ‘erase it from public conscience’
Yuval discovered actual irrefutable child murder beyond the Blood Libel. During the First Crusade, impatient folk tried to forcibly baptise Jews of Rein Valley in order to save their souls from the satanic cult of hate, as they saw it. Their refusal to be baptised was seen as stubborn adherence to Satan: for the pre-modern people, our present religious indifference was unacceptable. They saw a direct connection between faith and behaviour, and felt the need for communal worship, for unifying communion. A Jew permanently residing in a Christian land created a complicated situation: he was free from duty of brotherly love and could (and often did) act in anti-social way, for instance he practiced usury and sorcery. The Christians were particularly worried by the well-attended Jewish custom of cursing Gentiles. Every day Jews asked God to kill, destroy, humiliate, exterminate, defame, starve, impale Christians, to usher in Divine Vengeance and to cover God’s mantle with blood of goyim. Israel Yuval’s book offers its reader a good selection of bloodcurdling curses.
The Crusaders were non-racists. They did not think the Jews were irredeemably evil, but they rejected the ideology of hate and vengeance expressed in the curses. They also feared the curses, as much as Jews did. (In modern Israel, cursing is a criminal offence punishable by prison). Indeed, for Jews and for Christians of that time the curses were not just silly offensive words, but potent magic weapon. They offered Jews expulsion or conversion, this old-style equivalent of our modern psychological treatment meted out to adepts of totalitarian sects. At that time, the Slavs and the Scandinavians were also forcibly baptised, and it made eminent sense to baptise the Jews living in the Christian lands as well.