Pope Urban II's 1096 invocation mobilizes all of Christendom. For two centuries, from the reign of Gottfried of Bouillon to the reign of Louis the Saint, Europeans of various social strata rose under the banners of the Church to recapture from the enemy or defend the Holy Land. What drove them: religious feelings or political calculation? In the name of Christ, they killed the infidels, captured their cities - Nicaea, Antioch, Tire, Jerusalem, having founded the Latin Empire. For Muslims, this religious upsurge of Christians was nothing more than an aggression of barbarians. Emir Zengi and Hyp ad-Din, his son and successor, declared jihad, or holy war, on Christians. The myth of the invincibility of the Franks was dispelled. Saladin, the sultan of Egypt and Syria, dealt the Europeans a final blow: they were finally expelled from the Holy Land in 1291. The book of Georges Tat will acquaint you with the main stages of these bloody clashes between two worlds - Christian and Muslim.