After Boccaccio had taken up a permanent residence in Florence, he showed a lively interest in her political affairs, and fulfilled all the duties of a good citizen. In 1350 he was chosen to visit the lords of various towns of Romagna, in order to engage their cooperation in a league against the Visconti family, who, already lords of the great and powerful city of Milan, desired to extend their domains beyond the Apennines. In 1351 Boccaccio had the pleasure of bearing to the poet Petrarch the news of the restoration of his rights of citizenship and of his patrimony, both of which he had lost in the troubles of 1323, and during this visit the two geniuses became friends for life. They delved together into the literature of the ancients, and Boccaccio determined, through the medium of translation, to make the work of the great Greek writers a part of the liberal education of his countrymen. A knowledge of Greek at that time was an exceedingly rare accomplishment, since the serious study of living literatures was only just beginning, and the Greek of Homer had been almost forgotten. Even Petrarch, whose erudition was marvelous, could not read a copy of the _Iliad_ that he possessed. Boccaccio asked permission of the Florentine Government to establish a Greek professorship in the University of Florence, and persuaded a learned Calabrian, Leonzio Pilato, who had a perfect knowledge of ancient Greek, to leave Venice and accept the professorship at Florence, and lodged him in his own house. Together the Calabrian and the author of _La Fiammetta_ and the _Decameron_ made a Latin translation of the _Iliad_, which Boccaccio transcribed with his own hand. But his literary enthusiasm was not confined to his own work and that of the ancients. His soul was filled with a generous ardor of admiration for Dante; through his efforts the Florentines were awakened to a true sense of the merits of the sublime poet, so long exiled from his native city, and the younger genius succeeded in persuading them to establish a professorship in the University for the sole study of the _Divine Comedy_, he himself being the first to occupy the chair, and writing a _Life of Dante_, besides commentaries on the _Comedy_ itself. Mainly through his intimacy with the spiritual mind of Petrarch, Boccaccio's moral character gradually underwent a change from the reckless freedom and unbridled love of pleasure into which he had easily fallen among his associates in the court life at Naples. He admired the delicacy and high standard of honor of his friend, and became awakened to a sense of man's duty to the world and to himself. During the decade following the year 1365 he occupied himself at his home in Certaldo, near Florence, with various literary labors, often entertaining there the great men of the world.