Condottieri, leaders of the Italian mercenary armies that participated in the almost incessant warfare among the Italian states in the 14th and 15th centuries. Among the most celebrated leaders was the English adventurer Sir John Hawkwood (also called Giovanni Acuto), the commander of the White Company, who, after fighting in the wars between England and France, crossed into Italy and became captain general of Florence. Another was Francesco Bussone da Carmagnola, who fought first in the pay of Milan and then for Venice, was accused of treason, and executed by the Venetian Council of Ten. Bartolomeo Colleoni was a noted soldier who fought for both Milan and Venice and in 1454 became generalissimo of Venice. Francesco Sforza, the grandson of a peasant, also began his career as a condottiere, and in 1450 made himself duke of Milan. The Florentine political philosopher Niccolò Machiavelli stated that sometimes battles were fought by two bands of condottieri in which no one was killed except by accident. Such comparative bloodlessness has been attributed to the frequency with which the condottieri changed sides, making zeal against former or potential comrades undesirable.