Legnano was no overwhelming catastrophe, but it was ominous that citizen levies had defeated German knights in a fair field. Frederic's counsellors insisted that it was foolhardiness to pursue the war interminably, when at any moment the papal interest might gain the upper hand in Germany. Peace must be made at any cost with Alexander, and he would accept no peace from which the Lombards were excluded. Frederic yielded to the inevitable with a good grace. A treaty was concluded with the Pope in the same year (November 1176); a few months later, a six years' truce with the Lombards was arranged at Venice; and at Constance, in 1183, this was converted into a lasting peace. In form there was a compromise. The cities, while retaining the regalia and the free election of their consuls, recognised their allegiance to the Emperor and his appellate jurisdiction. In reality the Emperor had surrendered everything of value, and the cities ignored any stipulations in the treaty which were unfavourable to them. So matters remained until Frederic II, the grandson of Barbarossa, having firmly established himself in his Sicilian heritage, began to meditate a closer union between his dominions north and south of the Alps. The better to secure his communications with Germany, he prepared to enforce in Lombardy the imperial rights reserved at Constance (1226). At once the dormant Lombard League revived. The Alpine passes were so effectually blockaded that Frederic was left entirely dependent on his Sicilian forces. He turned the flank of the League at length, by an alliance with Ezzelin da Romano, the tyrant of Verona, which gave him access to the Brenner pass; but the League retaliated by lending support to his rebellious son, Henry, King of the Germans. So began another war in Lombardy. Legnano was brilliantly avenged on the field of Cortenuova (1237), where the Emperor routed the Milanese and captured the _carroccio_, the symbol of their independence. But he, like his grandfather, was worn out by the difficulties of siege warfare; and in 1240 he turned southward to reduce the States of the Church. One more attempt he made on Lombardy in the winter of 1247-1248. But a disastrous fiasco destroyed his hopes and gave a mortal blow to his prestige. For five months he blockaded Parma, and the city was at the last gasp, when he imprudently dismissed a part of his troops. The garrison saw their opportunity, and made a desperate sortie while the Emperor was absent on a hunting expedition. They surprised and burned the strongly fortified camp which he had named Victoria; his baggage and even his crown jewels were captured; more than half of his army were slain or taken, and the rest fled in confusion to Cremona (18th February 1248). It was necessary for Frederic to beat a retreat, and he appeared no more in Lombardy. His son Enzio, whom he left to represent him, was captured next year by the Bolognese and sentenced to perpetual captivity.