34. At this crisis, while Noureddin, the Sultan of Aleppo, and Amalric, the Christian King of Jerusalem, were the rival powers in Syria, occurred a circumstance which exercised considerable influence on the subsequent course of events, and which makes necessary a retrospective glance. 35. At the time of the first crusade Palestine was the scene of a violent contest between the Turks, who had poured down from the North, conquering as they went, and the Fatimites of Egypt, who had possessed Syria for nearly a century. The Turks had at first been irresistible. The Fatimites, however, had been able to recover Jerusalem from the hands of their enemies, and held it when besieged by the Christians. Interrupted in their conflict with each other for the sovereignty of Palestine, the Fatimites and Turks turned their arms with one accord against the invader. In the person of Noureddin the Turkish power was now increasing. The Fatimite dynasty of Egypt, meanwhile, had long been showing signs of decay, the caliphs having become mere tools in the hands of their viziers. In 1163 one of these viziers, Shawer, finding himself expelled from his post by a rival, sought refuge at the court of Aleppo, and applied to the sultan for assistance. Noureddin eagerly embraced an opportunity for obtaining a footing in Egypt, and sent two persons, Chyrkouh and his nephew Saladin, to displace the usurping vizier and re-establish Shawer. They, however, usurped the government, and Shawer applied to the King of Jerusalem, Amalric, for assistance. Amalric in turn attempted usurpation, and again the officers of Noureddin came to the aid of Shawer. The vizier paid the penalty of his fickleness by losing his head, and his post was occupied by Chyrkouh, who, while ruling Egypt as a vizier of the Fatimite caliph, was in reality the lieutenant of Noureddin. 36. On the death of Chyrkouh, Saladin was appointed to the viziership. The caliph fancied that he would now regain the control of his own dominions, but he little knew the character of his new vizier. Saladin soon effected a revolution in Egypt, declared the Fatimite dynasty to be at an end, and subjected the country once more to the nominal authority of the Bagdad caliphs, whom Noureddin professed to reverence as the supreme heads of the Mohammedan Empire. Nor did he stop here. He soon showed a disposition to shake off the supremacy of Noureddin, and the sultan of Aleppo was marching into Egypt to vindicate his authority, when he suddenly died in the year 1171.