The Sixth Crusade, that of Frederick II., is described in the chronicle of Richard of San Germano, a notary of the emperor, and in other Western authorities, e.g.
His later years were spent in strife with his son Frederick, and he died in 1230 at San Germano, whither he had gone to arrange the peace between the emperor Frederick II.
After the treaty of San Germano, which was made with Pope Gregory in 1230, and the consequent lull in the struggle with the Papacy, Frederick was able to devote some little attention to Germany, and in 1231 he sanctioned Rebellion the great Privilege of Worms. This was a reward to the princes for their efforts in bringing about the peace, and an extension of the concessions made in 1220.
On his return Frederick defeated the pontificals, and in 1230 peace was made at San Germano and the excommunication withdrawn.
In 1533 he left San Germano, and went to Rome, where he became tutor in the house of a Florentine gentleman named Galeotto Caccia.