The Frank occupation of Syria and the Holy Land had spread dismay throughout the whole of Islam; in their distress the followers of the prophet turned to Damascus, and saw in the rising greatness of its sovereign a fresh hope of retrieving their fortunes. Nûr-ed-dín 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 ‘Άdhid le dín 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-dín, who sent Esed-ed-dín Shírkóh, governor of Edessa, with a large army into Egypt. Dargham was defeated and slain, and the victorious Shírkóh claimed for his master Nûr-ed-dín 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. Shawer, as perfidious as he was ambitious, invited Amaury, King of Jerusalem, to aid him in ejecting his creditor. Shírkóh 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-dín. Fortunate would it have been for the Christian kingdom of Jerusalem had Amaury held to his agreement; but the favourable terms which had been accorded him inspired him with an undue confidence in his own strength, and, blind alike to his interests and his honour, he determined upon a fresh invasion. Accordingly, in the latter end of the year 1168, he led an army into Egypt, took possession of Bilbeis, and marched upon Cairo. The greatest consternation prevailed in the capital at the treacherous conduct of the Christian monarch, and the savage cruelty of his troops. Cairo was hastily surrounded with a wall and fortifications, and the old city was set on fire at the approach of the invaders, the conflagration raging for fifty-four days. In this extremity the Egyptian caliph piteously besought Nûr-ed-dín to lend him his aid; and, in order still further to excite his compassion, and depict the miserable plight to which they were reduced, and the danger to which they were exposed from the unbridled licentiousness of the invaders, El‘Άdhid enclosed locks of his women’s hair in the letter which contained his appeal. Shawer, in the meantime, endeavoured to avert the immediate calamity by making terms with Amaury, and the latter, dreading the arrival of the Damascene reinforcements, consented to raise the siege on receiving an indemnity of a million _dínárs_; a hundred thousand were paid down in ready money, and the Crusaders retired, in order to give the vizier time to collect the remainder. Nûr-ed-dín, on receipt of El ‘Άdhid’s letter, at once despatched Shírkóh to the relief of Cairo, with an army of eight thousand men, six thousand of whom were Syrians, and the remainder Turks, and a sum of two hundred thousand _dínárs_, as well as a large supply of clothes, arms, horses, and provisions. Shírkóh requested his nephew Yusuf Saláh-ed-dín (Saladin) to accompany him upon this expedition; but the latter, remembering the difficulties and dangers he had experienced at Alexandria, begged to be excused, and was only induced to accept a commission by an exercise of authority on the part of the sultan Nûr-ed-dín. El ‘Άdhid met Shírkóh on his arrival with every mark of respect and gratitude, and conferred upon him a magnificent robe of honour. The vizier Shawer was also a frequent visitor to the Damascene general’s tent; and assured the latter that although appearances had been against him, he had not willingly broken faith with him, and promised that the former agreement to pay Nûr-ed-dín a third of the revenue should now be complied with.