The Crusades, when Christians had no problem killing Jews all along the Crusader routes to the Holy Land.

The Crusades, where English Christian nobles killed Jews so that the British nobles could avoid having to repay debts to the local Jews.

The Crusades, where Christians killed people all along the route. Because that was so Christian of them.

Let’s also ignore the Western Christian Crusaders (4th Crusade) who decided to lay siege and ultimately sack Constantinople, which was still the Eastern Orthodox Christian home and center of the Eastern Roman Empire. The sacking of Constantinople led to its inevitable weakening that ultimately allowed the Ottoman Turks to overwhelm them in 1453.

It also led to the schism between Eastern and Western Christian Churches.