Who called for the First Crusade at the Council of Clermont in 1095?

The story behind the answer

At the Council of Clermont in 1095, the Roman pontiff answered Emperor Alexios I Komnenos’s plea for help against the Seljuk Turks by preaching an armed pilgrimage to aid Eastern Christians and reclaim Jerusalem. He offered a powerful spiritual incentive—remission of sins—which, along with the electrifying cry “Deus vult!” (“God wills it!”), mobilized knights across Western Europe and launched the First Crusade.

This moment reshaped medieval Europe: it bolstered papal leadership, redirected knightly violence into a “holy war,” and led to the capture of Jerusalem in 1099 and the creation of Crusader states. For context, Gregory VII had earlier entertained a similar idea but was consumed by the Investiture Controversy, while Innocent III later organized other crusades, including the ill-fated Fourth Crusade.