Which 1095 council is traditionally associated with Urban II’s call for crusade?

The story behind the answer

In November 1095, Pope Urban II preached a sermon urging Western knights to aid Eastern Christians and liberate the Holy Sepulchre. Chroniclers like Fulcher of Chartres and Robert the Monk record the promise of remission of sins for those who “took the cross,” and the crowd’s famed response, “Deus vult!” This call set in motion the First Crusade, with departures beginning in 1096.

Context helps sort the other councils: earlier that year at Piacenza, envoys of Byzantine emperor Alexios I requested Western military help, laying the groundwork. Melfi was chiefly about Church reform in southern Italy, and Bari (1098) addressed theological disputes with the Greek Church. The 1095 assembly also advanced Gregorian Reform—condemning simony and clerical marriage—showing how crusading ideals grew out of broader efforts to purify and mobilize Latin Christendom.