All that the conqueror now demanded was that the proud municipality should humble itself before him, swear allegiance, and promise not to interfere with the freedom of the smaller cities. On the 6th of September a procession of nobles and churchmen defiled before him, barefooted and clad in tattered garments, the consuls and patricians with swords hanging from their necks, the others with ropes round their throats, and thus, with evidence of the deepest humility, they bore to the emperor the keys of the proud city. "You must now acknowledge that it is easier to conquer by obedience than with arms," he said. Then, exacting their oaths of allegiance, placing the imperial eagle upon the spire of the cathedral, and taking with him three hundred hostages, he marched away, with the confident belief that the defiant resistance of Milan was at length overcome. He did not know the Milanese. When, in the following year, he attempted to lay a tax upon them, they rose in insurrection and attacked his representatives with such fury that they could scarcely save their lives. On an explanation being demanded, they refused to give any, and were so arrogantly defiant that the emperor pronounced their city outlawed, and wrathfully vowed that he would never place the crown upon his head again until he had utterly destroyed this arrant nest of rebels. It was not to prove so easy a task. Frederick began by besieging Cremona, which was in alliance with Milan, and which resisted him so obstinately that it took him seven months to reduce it to submission. In his anger he razed the city to the ground and scattered its inhabitants far and wide. Then came the siege of Milan, which was so vigorously defended that three years passed before starvation threw it into the emperor's hands. So virulent were the citizens that they several times tried to rid themselves of their imperial enemy by assassination. On one occasion, when Frederick was performing his morning devotions in a solitary spot upon the river Ada, a gigantic fellow attacked him and tried to throw him into the stream. The emperor's cries for help brought his attendants to the spot, and the assailant, in his turn, was thrown into the river. On another occasion an old, misshapen man glided into the camp, bearing poisoned wares which he sought to dispose of to the emperor. Frederick, fortunately, had been forewarned, and he had the would-be assassin seized and executed. It was in the spring of 1162 that the city yielded, hunger at length forcing it to capitulate. Now came the work of revenge. Frederick proceeded to put into execution the harsh vow he had made, after subjecting its inhabitants to the greatest humiliations which he could devise.