Flushed with his easy triumph, Frederick held in November a second Diet at Roncaglia. The most famous civilians of Bologna attended and declared the imperial rights so vigorously that Frederick took their order under his special protection, and gave doctors of laws the privileges of knights. [Sidenote: Diet at Roncaglia.] It was announced that the Emperor had resolved to take all his royal rights back into his own hands. The pleasure of the prince had the force of law, and no length of prescription could justify usurpation. But the Emperor was willing to reinvest both the lay and ecclesiastical lords and the towns with rights to which they had a lawful title. Nevertheless, the supreme magistrates of the towns were to be in all cases appointed by the king with the assent of the citizens. Instead of the aristocratic consulate, it was henceforth a main object of Frederick’s policy to establish a _podestà_ as the supreme governor of each town. This representative of the imperial power was generally a stranger, with no interest or sympathy in the town that he ruled, and universally detested as an intruder and a despot. Immediately after the dissolution of the Diet, Rainald of Dassel and Otto of Wittelsbach went round to the various Lombard cities to set up _podestàs_. Milan, disgusted at the Emperor’s ignoring the terms of their former capitulation, refused to receive its _podestà_, and broke into revolt. Other cities followed its example—one of which, Crema, was carried by assault by Frederick after a terrible siege. Milan held out for three years, and had to face the whole of Frederick’s power, until at last famine forced it to open its gates. Frederick hardened his heart to the prayers of the Milanese, and made a great favour of allowing them their lives. [Sidenote: Revolt and destruction of Milan.] The chief men of the city were kept as hostages; the walls and defences were destroyed; and the ancient inhabitants were forbidden to dwell in the open village that now represented the city of St. Ambrose, where a few ancient churches, conspicuous among which was the Basilica of the patron saint, alone arose amidst the ruins. The relics of the three Magi of the East were secured by Rainald of Dassel for his own church at Cologne, of which they have ever since remained the chief glory. The municipal independence of Italy seemed extinct. The Emperor was king as well as overlord.