The Italian troubles were hardly ended when the presence of the Emperor was urgently demanded at home. There were quarrels and complications to be settled everywhere. He travelled all over the Empire. Now he was at Passau and Vienna, again at Cologne and Utrecht. From the Reichstags at Ulm and Laufen he hurried to the eastern frontier and quelled the Hungarian uprising. Soon after this he was at the Reichstags of Speier and Nuremberg, organizing another expedition against Italy. His representatives there unfortunately had failed to conciliate his conquered enemies. Their passion for revenge had smouldered like a spark in the ashes. Even without their once powerful leader, Milan, the larger cities had leagued themselves against the Emperor. Pavia alone remained loyal to him. Frederick now devoted his entire attention to the restoration of order in the refractory cities, but his customary good fortune deserted him. A virulent pestilence quickly swept away a large part of his army, and those who had been weakened by illness were exposed to the fierce attacks of the Lombardians, who, emboldened by this disaster among the Germans, seized all the mountain passes in hopes of capturing the Emperor. Secret flight was his only hope of escape. With his true friend Conrad and a little band[14] of knights, he fortunately reached Savoy, and attempted to enter Germany by way of the mountains; but he was recognized by his enemies, who planned to murder him in the night. Their plot was discovered, however. After considering various ways of escape, a knight, Hermann of Siebeneich, who closely resembled the Emperor, offered to lie in his bed while Frederick made his escape. His enemies were not so inhuman as to punish the knight for his gallant act. Greatly depressed but not disheartened, Frederick returned to Germany, where he found plenty to occupy his attention. Henry the Lion, Duke of Brunswick and Saxony, the most powerful prince next to the Emperor, was sorely oppressing his neighbors. All of them had suffered from his depredations, the Archbishops of Magdeburg and Bremen being the special objects of his hatred. Frederick quickly ended the trouble, however, and made all concerned promise to keep the peace.