Frederick, responding to pressure by the new pope, organizes the Sixth Crusade.

In September 1227, when Frederick is at last ready to embark from Brindisi for the Holy Land, an epidemic breaks out among the crusaders, delaying the emperor's departure.

Even the master of the Teutonic Knights, Hermann of Salza, recommends that he return to the mainland to recuperate.

Frederick is excommunicated by Pope Gregory IX on September 29 for failing to honor his crusading pledge.

During the delay, he receives envoys from the late Saladin's nephew Sultan al-Kamil of Egypt, who, threatened by the ambitious designs of his Ayyubid brothers, is disposed to negotiate.