In the First Crusade, Bohemond of Taranto, Raymond of Toulouse, Godfrey of Bouillon, Tancred of Hauteville, Baldwin of Boulogne, and Peter the Hermit were the key figures from the Western Roman Empire.
The First Crusade was a costly activity, and there were no visible rewards at the starting of the war. When Warfare is about to happen, the Kings and Armies involving it always look for the reward after winning the war. But this wasn’t the case for the First Crusade because there was no material award and not even Physical wealth. Still, the armies involved in it because of Spirituality.