Meanwhile the Franks had met with several checks. The Turks under Zengi defeated them at Atharib in 525, and in 539 took Edessa from them. Thus the Franks began to be threatened from the north-east, and their opponents were consciously making plans for their final subjugation or expulsion. In 541 Zengi died and was succeeded by his son Nur ad-Din, who becomes the decisive factor in the affairs of western Asia and Egypt within the course of the next few years. At this time the Franks were distinctly on the decline, and the hopes built on the foundation of Jerusalem and other Latin kingdoms in Palestine and Syria were not being realised. The West began to feel that the First Crusade had failed in its effort, and so the Second Crusade, mainly the work of St. Bernard whose aims and intentions were above question, set out in 542 and attacked Damascus in the following year, the Crusaders then marching on Jerusalem. But the Second Crusade was an immediate and marked failure. Conditions were greatly changed from what they had been when the former Crusade arrived: there was now a strong Turkish power in Syria, and this was inclined and prepared to be aggressive. The Second Crusade was necessarily a failure. The only important result of Frankish invasion was the kingdom of Jerusalem which had been the work of the First Crusade. At this period of Egyptian history we are able to avail ourselves of the very interesting record which Osama has left of his own experiences in Syria and Egypt, a record which has been rendered accessible in the French translation of Derenbourg (_Vie d’Ousama_, Paris, 1886-93). Osama left Damascus in 538 and went to Cairo, where he was well received by al-Hafiz, who gave him a robe of honour and a house and other gifts. So long as Hafiz ruled Osama took no part in the public affairs of Egypt, but has left observations upon the course of events, but in the next reign he comes forward prominently as an adviser, and usually as an adviser of evil.