Pope Urban II was the religious leader from the Catholic Church who helped to organize the First Crusade in response to a conflict between the Byzantine Empire and the Seljuks.
Step-by-step explanation:
The religious leader from the Catholic Church who helped to organize the First Crusade was Pope Urban II. Urban II presented his idea of a religious war at a council in Clermont, France, in 1095, framing the conflict between the Byzantine Empire and the Seljuks as a fight between religions. This appeal, intended to aid the Byzantines, was transformed into a broader call for the liberation of Jerusalem and the Holy Land from Turkic control, marking the launch of the First Crusade. The pope's directive mobilized European aristocrats, clergy, and common people alike, resulting in a significant religious and military undertaking.