In November 1095 AD, Pope Urban II delivered an impassioned sermon at the Council of Clermont in France, calling upon Western European knights to launch a military expedition to aid the Byzantine Empire and reclaim the Holy Land, specifically Jerusalem, from Muslim control. His appeal sparked an unprecedented wave of religious zeal and military mobilization across Europe, initiating centuries of holy wars known as the Crusades. This campaign deeply altered relations between Christianity, Islam, and Judaism, and dramatically transformed Mediterranean trade routes and geopolitical power dynamics.

The Crusades radically shifted European literature by fueling the rise of troubadour poetry, chivalric romances, and songs of crusade ('chansons de croisade'). This blending of religious devotion with martial valor influenced major epic poets for generations, culminating in Torquato Tasso's Renaissance masterpiece, 'Jerusalem Delivered'.