Ferrara, formerly held from the Holy See by Azzo of Este, had become a Ghibelline stronghold and Azzo had been banished. To Venice happily Guelph and Ghibelline were but names. No factions destroyed her domestic peace; no feudal tyrants spoiled her citizens, or fury of popular jealousy flung itself against her nobles. But in Ferrara valuable trading rights granted by the Countess Matilda and maintained by the Guelphs were ignored by the Ghibellines. The restoration of these rights was made the price of her alliance with the Papal forces in an attack on Ferrara. The siege was a long one. The city was defended by the Imperialists under the most famous soldier of the day, Taurelli Salinguerra. At a critical moment the Papal legate appealed for help to the Doge, who, impelled by memories of his great predecessor, determined to take command of the forces in person. His son was left to rule in his absence, and after mass in the Church of Santo Spirito the expedition sailed forth, the Bucintoro, with the Doge on board, leading. Ferrara was subdued and the Doge was careful before leaving to exact from the restored Azzo the reinstatement of the Venetians in their former advantageous position as traders. Meanwhile the naval expedition had reached Apulia and after devastating many cities, returned to Venice with a rich booty. Tiepolo is said to have possessed a prodigious memory. “This note I have found,” says Sanudo, “_solum_ in one chronicle, yet it was the truth. This Doge was very wise and had great fame through all parts of the world. When any ambassadors came to deliver their suits he held his eyes shut: after he had heard he recited chapter by chapter and answered everything which they had expounded in such manner that all marvelled greatly at so profound a memory, for he was a most wise Doge.” On the 20th of May, 1249, Tiepolo, weary of his burden of the state, laid it down to retire to his house in S. Agostino.