The conquest of Anatolia, Syria and especially the Palestine by the Turks caused the awakening of a great excitement in the world of European Christians. The Crusades had started upon the encouragement and the instigation of the Pope Urbain II. The principal forces were the Turks that fought with the Crusades that came to Anatolia, Syria and Palestine with crowded armies. Pursuant to the invasion of the Jerusalem by the Crusades and the massacre of its people, the crusade count posts were founded in the Near East. Then, the Crusades started to gradually retreat as a result of the cruel struggles that were undertaken in order to abolish the Christian states that had been founded in the Muslim countries for centuries. Imadetdin Zengi captured Urfa in the year of 1144 and Selahaddin Eyyubi captured the Jerusalem from the Crusades in the year of 1187. Baybars who was the Sultan of the Egypt Turk Mameluke State eliminated all the residues of crusades in the coastal cities of Syria one by one. The second significant service of the Sultan Baybars for the Islam world was that he defeated the Mongolian Army that destroyed the entire Turkestan, Iraq and Iran and advanced towards the west in Ayn Calut in the year of 1260 and he stopped their progress. Bedrettin El-Ayni, one of the great historians of the Middle Ages has emphasised the importance of the Ayn Calut victory through stating that "Turks have saved the religion of Islam against the Mongols". On the other hand, Baybars invited El-Zahir's Son, Ahmed to Cairo that had took flight in Damascus when he escaped from the Mongolian massacre in the course of the invasion of Baghdad. Baybars declared that Ahmed was the Caliph and he was obedient to him on the date of 9th June 1261. Therefore, the Abbasi caliphate that was the spiritual leader of the Islam world for five centuries was restored. Ottoman State would undertake the position of the flag-bearer of the Islam world and it would fulfil this duty with honour and dignity for centuries.