POSITION OF THE TURKS. 331 hope of retrieving their fortunes. Nûr-ed-din did indeed become the instrument of the final overthrow and expulsion of the Christians ; but a slight digression is necessary to explain the circumstances which led to his introduction upon the scene. Dargham and Shawer, rival aspirants to the dignity of prime minister to El "Adhid le din Allah, last of the Fatemite caliphs of Egypt, had, by their struggles for power, involved, that country in civil war. Shawer, finding himself unable to cope with his more powerful foe, applied for assistance to Nûr-ed-din, who sent Esed-ed-din Shirkoh, governor of Edessa, with a large army into Egypt. Dargham was defeated and slain, and the victorious Shirkoh claimed for his master Nûr-ed-din the reward which Shawer himself had proposed, namely, a third of the revenues of the country ; and, on payment being delayed, proceeded to occupy Bilbeis, the capital of the eastern province, as security. Shawar, as perfidious as he was ambitious, invited Amaury, King of Jerusalem, to aid him in ejecting his creditor. Shirkoh was obliged to relinquish Bilbeis ; but, having received reinforcements from Damascus, he speedily returned, marched upon Cairo, and defeated the troops of the Fatemite caliph, and made himself master of Upper Egypt. His nephew Yusuf had been, in the meanwhile, sent against Alexandria, which place he captured, and gallantly defended for more than three months, against the combined forces of the Egyptians and Crusaders. At last, both the Christian and Damascene troops consented to evacuate Egypt, on consideration of receiving each a large sum annually out of the revenues ; and articles of peace were solemnly drawn up, and ratified by all the contending parties ; the Crusaders were, moreover, allowed to maintain a garrison at Cairo, ostensibly for the purpose of protecting the Egyptian government from aggression on the part of Nûr-ed-din. Fortunate would it have been for