Of Giovanni di Bicci de’ Medici’s two sons, Cosimo was by far the most remarkable. “The father,” writes Gibbon, “of a line of princes, whose name and age are almost synonymous with the restoration of learning; his credit was ennobled into fame; his riches were dedicated to the service of mankind; he corresponded at once with Cairo and London, and a cargo of Indian spices and Greek books were often imported in the same vessel.” For even when most deeply engaged in political matters, Cosimo always found time to attend to his business, and himself conducted the correspondence with the heads of the banks which were known throughout Europe and in Asia. All had orders to buy ancient manuscripts and rare books. As a lad he served in the Pisan war, and in 1414 was sent by his father in the suite of Pope John XXIII. to represent the bank at the Council of Constance. After the flight of the Pope, Cosimo left Constance in disguise and returned to Florence, where he was elected a Prior of the city in 1415, and again in 1417. Cosimo was forty when his father died in 1429. Ammirato describes him as of middle height, with an olive complexion, and of imposing presence. Machiavelli says that he applied himself so strenuously to increase the political power of his house that “those who had rejoiced at Giovanni’s death, now regretted it, perceiving what manner of man Cosimo was. Of consummate prudence, staid yet agreeable presence, Cosimo was liberal and humane. He never worked against his party nor against the State, was prompt in giving aid to all, and his liberality gained him many partisans among the citizens. Chief amongst those who helped to consolidate his power were Averardo de’ Medici and Puccio Pucci--Averardo by his audacity, Puccio by his prudence and sagacity, augmented his popularity and greatness. The advice and the sane judgment of Puccio were so highly esteemed and so well known by all that Cosimo’s party was not called by his name but by that of Puccio.”[4]