Â Â Â Â Â Â Â Â Â Â Â Pope Innocent III (p.1198-1216), who was perhaps the most ardent supporter of Crusade to hold the Papacy, issued the Papal Bull Quia maior in April 1213 calling for a new Crusade to recapture Jerusalem.Â This Bull set the standard for all future Crusading Bulls; in it, Innocent introduced many new concepts that widened the appeal of Crusading in Christendom. This was the first time that the indulgence had been expanded to include those who could not go on Crusade, they could gain the indulgence by supporting the Crusade financially. Innocent intended for this new Crusade to be led by the church and he worked tirelessly to see the Crusade come to fruition.
Â Â Â Â Â Â Â Â Â Â Â The response to the new call for Crusade was tremendous throughout Europe except for France where the nobility was engaged in suppressing the Albigensian heresy. Duke Leopold VI of Austria (1176-1230) led a large contingent from Austria on Crusade. In Hungary, Andrew II (1205-1235) had taken the cross during the Fourth Crusade but had not fulfilled his vow so he now joined this new effort in its fulfillment. A churchman Oliver of Paderborn the Bishop of Cologne gathered a large army in Northwest Germany, Holland, and Flanders, which he then led on the Crusade himself. Oliver also wrote an account of the Fifth Crusade that is one of the most valuable sources extant. Frederick II, Holy Roman Emperor (1205-1250) also took the cross promising to lead a massive army of Germans but he first had to cement the control of his empire.
Â Â Â Â Â Â Â Â Â Â Â The Crusade was scheduled to leave Europe in the spring of 1217 but Innocent III would not live to see the Crusade depart, he died on 16 July 1216. The new Pope, Honorius III (p.1216-1227) was just as eager to see the Crusade succeed.Â The Hungarian and Austrian contingents did not sail for the Holy Land until late 1217 and went to straight to the capital of the Crusader kingdom at Acre. Frederick II was stalling for time before leaving on Crusade; he had yet to consolidate control of the empire in his hands.
Â Â Â Â Â Â Â Â Â Â Â Once they arrived in Acre, the Crusaders were joined by armies from Antioch as well as the forces of the Kingdom of Jerusalem. The problem was what to do with the army that would have a lasting effect. The leaders agreed at a council that the only way to effect lasting security for the kingdom would to be to conquer Egypt, which was the center of Muslim power in the Levant during the Middle Ages. It was also agreed that any attack on Egypt would have to wait until the arrival of Frederick II with his large German army. The Crusaders occupied themselves over the winter with some minor campaigns while awaiting the Germans.
Â Â Â Â Â Â Â Â Â Â Â In January 1218, King Andrew II of Hungary announced that he had fulfilled his vow and returned home. The remaining Crusaders were too few in number to attempt the conquest of Egypt but Oliver of Paderborn and some Italians arrived in the spring. Frederick continued to send assonances of his imminent departure but the Crusaders decided to begin the attack with the troops they had available. They chose to attack the coastal city of Damietta to provide a beachhead for an assault on the Cairo. The Crusaders began the siege of Damietta in May 1218, they had no idea that the siege would last for eighteen months. The Muslims of Egypt were led by one of the nephews of Saladin, Al-Kamil (r.1218-1238) he was determined to defend the Egyptian heartland from the Crusaders.
Â Â Â Â Â Â Â Â Â Â Â Initially the Crusaders could not dislodge Al-Kamil from his camp and thus could not complete the encirclement of the city but in February 1219 Al-Kamil abandoned his camp while responding to a palace coup. The Crusaders occupied his camp unopposed and completed the encirclement of Damietta. The siege continued while conditions in the city got worse and worse. On 4 November 1218 the Crusaders entered the city through an unguarded tower and captured Damietta after an eighteen month siege. According to Oliver of Paderborn, “out of 80,000 inhabitants only 3,000 were left alive when the city fell.â€Â Al-Kamil retreated down-river to the town of Mansourah where he built a fortified camp to stop any further Crusader advance.
Â Â Â Â Â Â Â Â Â Â Â The Crusaders waited throughout 1220 for the arrival of Frederick II. The German armies began to arrive in Egypt in May 1221. With the arrival of fresh troops, the Crusaders prepared to march on Mansourah despite being counseled against the move until Frederick II arrived with his complete army. The Christians camped on a peninsula outside the city in July 1221, by August, the rising Nile had prevented the Christians from being resupplied, and on August 26, the army began its retreat. Muslim troops quickly broke dike walls and the Crusaders were trapped in a newly formed sea of mud.Â Two days later the Crusaders were forced to negotiate
Â Â Â Â Â Â Â Â Â Â Â The Christians agreed to leave Egypt and cede Damietta in return for an eight-year truce and the return of the True Cross. The Fifth Crusade had failed, having achieved none of its objectives. The failure was mainly caused by the lack of leadership and the Crusaders false hope that Frederick would arrive and lead them to glorious victory. The final slight was that the True Cross would not be returned, AL-Kamil did not have it.
 Madden, Thomas, F. ed. The New Concise History of the Crusades, p.143
 Ibid., p. 146
 Maalouf, Amin. The Crusades through Arab Eyes. p. 226
 Madden. p. 155