Why did christians attack jews during the crusades?

they wanted revenge for jewish attacks on christians

jews were trying to regain the holy land for themselves

jews had allied with muslims

some christians viewed jews as enemies of christianity

Some Christians viewed Jews as enemies of Christianity is your best answer.

As in the bible, it states that it was the Jews that wanted Jesus (whom the Christians believed to be the son of God) to be crucified, and so in return, the crusaders began to slaughter most of them. This was inexcusable, and led to the Church having to provide established order and justice.

~