The indiscrinate massacre of all Muslims in Jerusalem, be they man, woman, or child, combatant or invalid, was murderous zealotry at its most vicious. So was the mass killings of Jews in Germany by Crusaders passing through on their way to the Holy Land in 1096, and the remaining 200 years of the Crusades provide plenty more examples - unless you feel that Christianity needed "defending" from the little Jewish children of Mainz.
Murder by Muslim Wahabbis was and is backed by the Koran.