Pope Urban II that was caused by the Great Schism of 1054. Others believe that Urban saw this as an opportunity to gain legitimacy as the pope as at the time he was contending with the antipope Clement III. A third theory is that Urban felt threatened by the Muslim incursions into Europe and saw the crusades as a way to unite the christian world into a unified defense against them. The most important effect of the First Crusade for Urban himself was the removal of Clement III from Rome in 1097 by one of the French armies. His restoration there was supported
Pope Lucius II Pope of his temporal power. The principal groups involved in this movement were the merchants and artisans, while the urban nobility kept their neutrality. The Senate, which practically took all temporal power from the Pope during the pontificate of Innocent II, had been managed with considerable skill and firmness by Lucius at the beginning of his pontificate, convincing many senators to either leave the Capitoline Hill or to lay down their magisterium. Now, encouraged by Lucius II's defeat, the Senate, led by Giordano Pierleoni, brother of the former Antipope Anacletus II, rebelled against Lucius II, driving out the papal prefects