On June 2, 1289, the new captain, Narbonne, took the field with an army of one thousand horse and ten thousand foot soldiers of the League. It comprised the flower of the Florentine nobles and commons, including six hundred of the best-equipped knights ever furnished by the city. Prato, Pistoia, Sienna, and all the allies, including the Guelphs of Romagna, had sent their due contingents. Meanwhile the Aretines had collected all the Ghibellines from neighbouring cities, and were encamped at Bibbiena with eight hundred horse and eight thousand foot, under the command of their captains, the greatest of whom was the daring Bishop Guglielmo degli Ubertini. On finding that he could not make terms with Florence to secure his own strongholds, without being exposed to the vengeance of the Aretines, he had plunged into the war with youthful ardour. His conduct was arrogant and full of assurance; for he relied on his own courage and that of his men, and despised the Florentines, because, so he said, they were as sleek as womenfolk. On the 11th of June the two armies met in the plain of Poppi, near Campaldino, where the engagement began. The battle is known by that name, and rendered all the more celebrated by the fact of Dante Alighieri--then young and unknown--having fought in it. The Florentines had placed a mixed host of infantry, crossbowmen, and bucklermen in the van, and their wings were formed of 150 skirmishing light horse, who were all picked men. Vieri de' Cerchi was among the latter; for, having been entrusted with the choice of those of his _sestiere_, he insisted, in spite of illness, on accompanying his son and nephews to the battlefield. In the rear of the first division a stronger force of heavy cavalry and infantry was drawn up, with the baggage-train behind. Corso Donati led a band of about 250 foot and horse from Lucca, Pistoia, and foreign parts. He was Podestà of Pistoia at the time, and was directed to hold his reserve back until the commander-in-chief gave the signal to advance. On either side there was a fever of emulation between the Guelphs and the Ghibellines, and to gratify the ambition of their respective leaders, some were awarded the honour of knighthood that day, in order to spur them to greater feats. The Florentines were under orders to await the enemy's charge, and Messer Simone dei Mangiadori of San Miniato shouted to his men, "Signori! our Tuscan battles used to be won by vigorous assault, but are now to be won by standing still." The Aretines, on the contrary, trusting to their own courage and their leader's skill, made so impetuous a charge to the cry of "_Viva San Donato!_" that the Florentine army wavered, and gave way before the shock. Nearly all the light horse were hurled from their saddles, and the main body fell back. But the foot soldiers flanking the second corps moved forward to the cry of "_Narbona cavaliere!_" and by threatening to surround the enemy,