Frederick the Second of Germany, who had engaged to lead a strong force into Syria, was so long prevented by domestic cares from fulfilling his promise, that he incurred the resentment of the pope, who actually pronounced against him a sentence of excommunication.[174] The emperor, at length, was induced to marry Violante, the daughter of John de Brienne, and accept as her dowry the kingdom of Jerusalem. In the year 1228 he arrived at Acre, with the view of making good his pretensions to the sacred diadem,--an object which he finally attained, not less by the connivance of the sultan than by the exertions of his military companions. The son of Saphadin felt his throne rendered insecure by the ambition or treachery of his own kindred, and was therefore much inclined to cultivate an amicable feeling with so powerful a prince as the sovereign of Germany. In pursuance of these views a treaty was signed, providing that for ten years the Christians and Mussulmans were to live on a footing of brotherhood; that Jerusalem, Jaffa, Bethlehem, Nazareth, and their dependencies, were to be restored to the former; that the Holy Sepulchre was likewise to be given up to them; and that the people of both religions might offer up their devotions in that house of prayer, which the one called the Temple of Solomon, and the other the Mosque of Omar. Thus the address or good fortune of Frederick more effectually promoted the object of the Holy Wars than the heroic phrensy of Richard Coeur de Lion; many of the disasters consequent on the battle of Tiberias were wiped away; and the hopes of Europe for a permanent settlement in Asia appeared to be realized. But the emperor had performed all these services while the stain of excommunication was yet unremoved from his character. The fidelity of the knights, accordingly, whose oaths had a reference to the supremacy of the church, and the attachment of the clergy, could not be relied upon. Hence, when he went to Jerusalem to be crowned, the patriarch would not discharge his office; the places of worship were closed; and no religious duties were observed in public during his stay. Frederick repaired to the Church of the Holy Sepulchre, surrounded by his courtiers, and boldly taking the crown from the altar, placed it on his own head. He then issued orders for rebuilding the fortifications of his eastern capital; after which he returned to Acre, whence he almost immediately set sail for Europe.[175]