great general, Carmagnola, turned the scale. The Florentine League was concluded and Carmagnola received the command of the Venetian forces.
Thus the Republic embarked upon a struggle for supremacy as a land-Power in northern Italy. But she was soon to prove the truth of Mocenigo's dying words. The first campaign ended in the acquisition of Brescia and the Bresciano by Venetian troops, but not by Carmagnola. He had no sooner brought his forces under Brescia than he asked leave to retire for his health to the Baths of Abano; and his conduct from the very first roused those suspicions which eventually led to his doom. The second campaign gave Bergamo to the victorious Republic. But the suspicions of Venice were increased by finding that the Duke of Milan was in communication with Carmagnola and was prepared to conclude a peace through him as intermediary, suspicions confirmed by the dilatory conduct of their general after the victory at Maclodio, when nothing lay between him and Milan. At the opening of the third campaign against Visconti, the Republic endeavoured to rouse their general to vigorous action by making him large promises if he would only crush the Duke and take his capital. But nothing would stir Carmagnola from his culpable inactivity. The truth was that he cared not a jot for Venetian interests; like all mercenaries he was playing his own game, and that did not counsel him to press Visconti too hard, for it was always possible that he might one day find himself again in the Duke's service.
The patience of the Republic was exhausted at last. Carmagnola was summoned to Venice on the plea that the government wished to consult him. He was received with marked honour. His suite was told that the general stayed to dine with the Doge and that they might go home. The Doge sent to excuse himself from receiving the Count on the score of indisposition. Carmagnola turned to go down to his gondola. In the lower arcade of the palace he was arrested and hurried to prison. He was tried by the Council of Ten on the charge of treason and executed in the Piazzetta of St Mark (1432).
Notwithstanding their difficulties with their mercenary commander, the Venetians had made very solid acquisitions during these wars with Visconti. Brescia and Bergamo were now permanently added to the land empire of the Republic, and the title was confirmed by an imperial investiture at Prague in 1437, in which Venetian dominions are defined as all the land di qua, that is east of the Adda,—very nearly the extreme limit of mainland possession ever touched by the Republic.
But the possession of Brescia and Bergamo was not likely to be left undisputed by Filippo Maria Visconti; and a long series of campaigns, conducted by such generals as Gonzaga and Gattamelata, exhausting to the treasury and unprofitable to the State, was only brought to an end by the death of the Duke of Milan in 1447. During this period, however,