Urban II was a pope who called for help in retaking the Holy Land, because Christian pilgrims to Palestine reported that they had been persecuted by the Turks.
When the Turks then threatened to invade the Byzantine Empire and take Constantinople, Byzantine Emperor Alexius I made a special appeal to Urban for help. This was not the first appeal of its kind, but it came at an important time for Urban. Wanting to reinforce the power of the papacy, Urban seized the opportunity to unite Christian Europe under him as he fought to take back the Holy Land from the Turks.
