Of all the princes of the middle ages, no one evinced more ambition than Henry VI.; his imagination, say historians was filled with the glory of the Cæsars, and he wished to be able to say with Alexander, _all that my desires can embrace belongs to me_. Tancred, a natural son of William II., king of Sicily, chosen by the Sicilian nobility to succeed his father, was recently deceased; and the emperor, who had espoused Constance, the heiress of a throne founded by Norman Crusaders, and desirous of establishing his claims, judged that the time was come to carry out his designs and achieve his conquests. The expedition of which the Holy See desired him to be the leader, was exceedingly favourable to his ambitious projects; when, promising to defend Jerusalem, he only thought of the conquest of Sicily; and the conquest of Sicily had no value in his estimation but as opening the road to Greece and Constantinople.[13] At the same time that he professed entire submission to the will of the head of the Church, he endeavoured to form an alliance with the republics of Genoa and Venice, promising them the spoils of the conquered; but in his mind he nourished the hope that he should one day overthrow the Italian republics and lower the authority of the Holy See, and upon their remains revive, for himself and his family, the empire of Augustus and Constantine. Such was the prince to whom Celestine sent an embassy, and whom he wished to persuade into a holy war. After having announced his intention of taking the cross, Henry convoked a general diet at Worms, in which he himself exhorted the faithful to take up arms for the defence of the holy places. Since Louis VII., king of France, who harangued his subjects to induce them to join in the crusade, Henry was the only monarch that had mingled his voice with that of the preachers of the holy war, to make his subjects acquainted with the sufferings and complaints of the Church of Jerusalem. His eloquence, celebrated by the historians of his time, but above all, the spectacle presented of a great emperor himself preaching a holy war against the infidels, made a profound impression upon the multitude of his auditors.[14] After this solemn address, the most illustrious of the prelates assembled at Worms ascended the evangelical pulpit to keep up the rapidly increasing enthusiasm of the faithful; during eight hours nothing was heard but the groans of Sion and the city of God. Henry, surrounded by his court, assumed the symbol of the Crusaders; a great number of German nobles followed his example, some to please God, _and others to please the emperor_. Among those who took the oath to combat the Saracens, history names Henry duke of Saxony; Otho marquis of Brandenburgh; Henry count palatine of the Rhine; Herman landgrave of Thuringia; Henry duke of Brabant; Albert count of Apsburg; Adolphus count of Schwemburg; Henry count of Pappenhein, marshal of the empire; the duke of Bavaria;