In fact, the first pretext for strife, at least as related by Villani (vi. 2), is futile to the point of utter absurdity. Many ambassadors attended the coronation of the Emperor Frederic II. in Rome (1220), and among them, says the chronicler, were those of Pisa and Florence, who had long eyed one another with distrust. It chanced that one of the Florentine ambassadors, while feasting with a cardinal, begged the gift of a certain very beautiful dog, and his host promised to grant it. The next day the cardinal entertained the Pisans, and one of them, happening to make the same request, the animal was promised likewise to him. But the Florentine, being the first to send for the dog, he actually obtained it. This led to quarrels and violence, not only on the part of the ambassadors and their trains, but also between all the Pisans and Florentines in Rome at the time. We can hardly assign any historical value to this tale; but it shows that the amount of ill-feeling between the rival states rendered any trifle a sufficient pretext for bloodshed. The real fact, even according to the testimony of Sanzanome, is that Pisans and Florentines came to blows in Rome. The Pisans were the assailants, but had the worst of the bout. There was great wrath in Pisa at the news of the riot, and as a speedy reprisal all Florentine merchandise in the town was made confiscate. Florence then seems to have done her utmost to avoid open war, but to no purpose. Preparations went on for some time on either side, and then in 1222, when war had burst forth between the Lucchese and Pisans, the Florentines profited by the opportunity to attack the latter near Castel del Bosco, defeated them, and, according to the chroniclers, carried off thirteen hundred prisoners. Other attacks ensued, and various small castles were captured between this time and 1228, when we see the Florentines engaged in more serious strife with the Pistoians, and reducing them to accept their terms. It is in 1228 that we find the first mention of the _Carroccio_ on a Florentine battle-field.[237] The Milanese had been the first to use the _Carroccio_, but in course of time, and with slight modifications, the custom had been adopted by the other Italian cities, who, with increasing wars and larger forces, recognised the need of a rallying point in their midst. The _Carroccio_ was a chariot drawn by oxen with scarlet trappings and surmounted by two lofty poles bearing the great banner of the Republic, swinging its red and white folds on high. Behind, on a smaller car, came the bell, called the _Martinella_, to ring out military orders. For some time before a war was proclaimed the _Martinella_ was attached to the door of Sta Maria in the New Market, and rung there to warn both citizens and enemies to make ready for action. The _Carroccio_ was always surrounded by a guard of picked men; its surrender was considered as the final defeat and humiliation of the army.