The end goal was not Constantinople, but Christ’s sepulcher in Muslim-ruled Jerusalem. If Byzantine emperors could not protect Christian interests there, Urban reasoned, popes would step in. They would not just save Byzantium. They would usurp the role of Roman emperors as guardians of the holiest places in the Christian world.
# From previous Investiture Controvery:
This is the strongest action where Popes could prove superiority over Holy Roman Emperor as the highest authority of God's vicar on earth
