Why was the 1st crusade launched?

The First Crusade was launched in 1096 primarily in response to a call for help from Byzantine Emperor AlexiOS I Komnenos, who sought assistance against Muslim incursions into his territory. Pope Urban II initiated the Crusade at the Council of Clermont in 1095, aiming to reclaim Jerusalem and the Holy Land for Christianity. Additionally, the Crusade sought to unite warring factions within Europe and redirect their aggression toward a common enemy, thereby reinforcing the power of the Church. The promise of spiritual rewards, including the forgiveness of sins, motivated many knights and commoners to participate.