The mutual hatred of the Ardinghelli and the Salvucci now blazed out afresh. Temporarily allayed by the appearance of some three hundred Florentine cavalry in the town, it came to a head in 1352. In a street brawl, a certain Ser Ilario struck Michele di Pietro, one of the Nine; Rossellino di Messer Gualtieri degli Ardinghelli (the brother of the Primerano already mentioned), who was present, was made responsible and fined. The Salvucci declared that Bartolommeo Altoviti, who was Captain of the town for the Florentines, had favoured Rossellino, and contrived that he should be succeeded by Benedetto di Giovanni Strozzi. Benedetto was easily convinced by them that Rossellino and Primerano were plotting with Altoviti against him. He promptly arrested the two brothers, "young men of great expectation and following," says Matteo Villani, "and Guelfs by disposition and birth," and imprisoned them. They threw a letter out of their prison tower, calling upon their friends to deliver them. It fell into the hands of the Captain, who, impelled "either by zeal of his office or by his own evil disposition or by the instigation of the Salvucci, their enemies," determined to put them to death. The Commune of Florence, believing them innocent, sent an express command to Benedetto that he should not take their lives: but the Elsa had risen in flood, and the messengers could not pass that night. The Captain, hearing that they were on the way, hurried on the execution; on August 9th, he had the two young nobles publicly beheaded in the Piazza at the foot of the steps of the Palace, together with the supposed accomplice to whom they had written the fatal letter.