Early in 1191 Henry VI. crossed the Alps to Italy. The mutual rivalries of the Lombard cities made it improbable that he would have much difficulty with the north. He prudently sought the friendship of both the rival leagues, whose feuds were now distracting Lombardy. He won the support of Pisa and Genoa, which alone had fleets strong enough to convey him to Sicily. In his anxiety to isolate Tancred, he strove to conciliate Clement III., who had been allowed to live in Rome on the condition of recognising the autonomy of the city. [Sidenote: Celestine III., 1191–1198.] But in March 1191 the pacific Clement died, and his successor, the Roman Cardinal Hyacinth, who took the name of Celestine III., was a weak and petulant old man of more than eighty years of age, who feared both the union of the Empire and Sicily, and an open breach with Henry. Henry demanded his coronation as Emperor, and Celestine strove to defer it by postponing his own consecration as Pope. Henry now marched to the neighbourhood of Rome, and took possession of Tusculum, which, in its bitter hatred of the Romans, had implored for an imperial garrison. He resolved to hasten his coronation by winning over the Romans, and with that object he treacherously handed over Tusculum to them. The Romans wreaked a hideous vengeance on their hated enemy. Tusculum was so absolutely demolished that no later attempt was ever made to repeople it. In later times Frascati, lower down the hill, became a populous town; but the ruins of Tusculum still testify to the completeness of the Romans’ vengeance. Henry’s stroke of policy met with immediate success. On April 14th Celestine was consecrated, and next day he crowned Henry and Constance. [Sidenote: Failure of the attack on Apulia, 1191.] Triumphant over the Papacy, Henry now marched against Tancred. At first he was conspicuously successful, and Naples alone still held out for Tancred. It was besieged by Henry on the land side, while the galleys of Pisa and Genoa blocked all access to it by sea. The strenuous resistance of Naples soon shattered the Emperor’s hopes. The Sicilian admiral, Margarito, drove away the Pisans, and re-opened communication between Naples and Sicily. The south Italian summer brought plague and fever into the German host. A fierce national reaction against the Northerners swept through southern Italy. Baffled and beaten, Henry raised the siege and returned to Germany.