The First Crusade originated in Rome in 1094, when Pope Urban II declared that the Catholic states of Europe, mainly England, France, and the Holy Roman Empire, to declare a crusade against the Orthodox Christian Byzantines and their rapidly expanding Muslim community, and declared the citizens of the Byzantine Empire heretics. The Pope spent two years campaigning for troops, until he had raised an army of 35,000 soldiers, 30,000 infantry and 5,000 cavalry, to invade the Byzantine Empire. The Pope's plan was to send the army of Crusaders by sea to capture the Holy Land, before moving to capture Constantinople.