forces of the kingdom and fortifying the coastal towns. The emperor was delayed while his ships were refitted. He sailed on 8 September 1227, but before they reached their first stop, Frederick was struck with the plague and disembarked to secure medical attention. Resolved to keep his oath, he sent his fleet on to Acre. He sent his emissaries to inform Gregory IX of the situation, but the pope did not care about Frederick's illness, just that he had not lived up to his agreement. Frederick was excommunicated on 29 September 1227, branded a wanton violator of his sacred oath taken many times. Frederick made his last effort to be reconciled with Gregory. It had no effect and Frederick sailed from Brindisi in June 1228. After a stop at Cyprus, Frederick II arrived in Acre on 7 September 1228 and was received warmly by the military orders, despite his excommunication. Frederick's army was not large, mostly German, Sicilian and English. Of the troops he had sent in 1227 had mostly returned home. He could neither afford nor mount a lengthening campaign in the Holy Land given the ongoing War of the Keys with Rome. The Sixth Crusade would be one of negotiation. After resolving the internecine struggles in Syria, al-Kamil's position was stronger than it was a year before when he made his original offer to Frederick. For unknown reasons, the two sides came to an agreement. The resultant Treaty of Jaffa was concluded on 18 February 1229, with al-Kamil surrendering Jerusalem, with the exception of some Muslim holy sites, and agreeing to a ten-year truce. Frederick entered Jerusalem on 17 March 1229 and received the formal surrender of the city by al-Kamil's agent and the next day, crowned himself. On 1 May 1229, Frederick departed from Acre and arrived in Sicily a month before the pope knew that he had left the Holy Land. Frederick obtained from the pope relief from his excommunication on 28 August 1230 at the Treaty of Ceprano. The results of the Sixth Crusade were not universally acclaimed. Two letters from the Christian side tell differing stories, with Frederick touting the great success of the endeavor and the Latin patriarch painting a darker picture of the emperor and his accomplishments. On the Muslim side, al-Kamil himself was pleased with the accord, but other regarded the treaty as a disastrous event. In the end, the Sixth