If
we define the Crusades as the Holy wars were fought for the sake of Jerusalem and its kingdom, then Pope Urban II was the founder of Crusades. But if we recognize them as the Battles have been fought on the behalf of Pope, i.e Teutonic wars against the Pagan tribes of north and Baltic region, Campaigns of Castile against the Moros (Muslims) of Spain. Then Pope Urban II wasn't the first, who starts the Crusades.
According to Sir George W Cox,
If Urban II. gave his blessings to the missionaries who were to convert the Saracens at the point of the sword, the papal benediction had been given nearly thirty years before (1st Crusade) at the instigation of Hildebrand to the expedition by which Norman William (William the Conqueror, also was titled as "William the Bastard" in the history ) hoped to crush the free English people and usurp the throne of the king whom they had chosen.