On the day of his accession to power Gregory IX. issued a proclamation for all the sovereigns of Christendom to unite in a new crusade, and openly threatened Frederick with his ecclesiastical vengeance if he longer postponed the fulfilment of his vow. He accused the emperor’s delay with being due to luxury, if not sensuality, in living. The former charge probably had in it a measure of truth, for Frederick’s court at Palermo, where he spent more time than in his northern capital, was the centre of gayety, not only among the Christians, but to a certain extent for Mohammedans. Many of the fairest women of Asia and North Africa graced his salons. It might also be imagined of Frederick that his faith was not of that intense and credulous nature which foresaw a heavenly crown awaiting his exploits in the Holy Land. Equally detrimental to his repute for crusading zeal were the courtesies he was exchanging with Malek-Kamel, Sultan of Egypt. It was even rumored that he had made alliance with this sultan, pledging help against the rival Sultan of Damascus, on condition of the restoration of Jerusalem. But the sincerity of Frederick was proved by the gathering of his fleets and the massing of his armaments at Otranto. The fame of his leadership attracted the noblest of Germany. Among them was Ludwig, Landgrave of Thuringia, noted for having won the hand of Elizabeth, daughter of Andrew II. of Hungary, who in her girlhood had attained renown for her asceticism and charities, and died (1231) at the age of twenty-four, to be canonized as the fairest saint of the middle ages. From distant England many came at Frederick’s call, and further impelled by visions of the Saviour on the cross of fire which appeared in that northern sky. The season was intensely hot, and gendered a fever fatal to the crusaders who were gathered in southern Italy. Among its victims was Ludwig, leaving his faithful spouse to keep his memory revered by her refusal to marry any one of the numerous kings who were attracted to her feet. Many bishops and thousands of pilgrims succumbed to this plague. Frederick sailed, but only to return in three days, seeking hospital in Otranto.