In June Frederick again took ship at Brindisi, and landed in September in Acre. His wife, Isabella of Brienne, died before his embarkation, on the birth of their son Conrad, but Frederick still claimed the crown of Jerusalem. Gregory now forbade the excommunicate Emperor from presumptuously undertaking the holy work, and commanded the faithful to withdraw from his armies. As Frederick still persisted, the sentence of excommunication passed because of his refusal to become a Crusader was renewed because he went to the Holy Land without reconciling himself to the Church. The Patriarch of Jerusalem and the Orders of the Temple and the Hospital obeyed the papal command. But the rash violence of the Pope overreached itself, and many Crusaders, conspicuous among whom was the young Teutonic Order and its famous master, Hermann of Salza, did not scruple to follow Frederick to battle. Public opinion blamed the Pope for his rigour, and a contemporary said that Frederick was the victim of Gregory, as Christ was the victim of Caiaphas. Though not unprepared for battle, Frederick trusted more to negotiation than to his arms. Long before his departure for Palestine, he had been conducting friendly negotiations with El-Kamil, the Sultan of Egypt. In February 1229 he concluded a ten years’ truce with the Sultan, by which Bethlehem, Nazareth, and Jerusalem were restored to the Christians, on condition only that the Mosque of Omar remained in Saracen hands. On Mid-Lent Sunday Frederick took the crown of Jerusalem from the high altar of the Church of the Holy Sepulchre, and placed it on his own head. But the Patriarch cast an interdict over the Holy Places, and no priest could be found to hallow the coronation by celebrating the offices of the Church. Frederick gave fresh cause for scandal by visiting the Mosque of Omar. He soon returned to Acre, and in June was back in Italy. Despite the thunders of the Church, the excommunicate Emperor had done more for the Christian cause than a generation of orthodox pilgrims. Hermann of Salza declared with good reason that Frederick could have obtained still better terms for the Christians had it not been for the hostility of Pope and clergy.