Italian rulers sent not only diplomats to the Burgundian court but also princes. Leonello d'Este, marquis of Modena and Ferrara, sent his illegitimate son Francesco. Lodovico Gonzaga, marquis of Mantua, sent Rodolfo, the fourth of his five sons. King Ferrante of Naples sent his second son Federico. Galeazzo Maria, duke of Milan, thought for a time of sending his younger brother Lodovico. Of course, the reasons for the presence of Italian princes at the Burgundian court were not so predominantly political as in the case of the diplomats. For the princes and noblemen of western Europe, the Burgundian court represented a form of finishing school where they could learn the arts and etiquette, not only of politics, but also of warfare, chivalry and courtly life. This was certainly true of Francesco d'Este and Rodolfo Gonzaga, although political reasons were uppermost in the case of Federico d'Aragona and of the proposed visit of Lodovico Sforza. There were, in fact, perceptible differences between these princes in terms both of their rank and of the duration and purpose of their visit. Rodolfo Gonzaga and Francesco d'Este were scions of what were only, in political terms at least, second-rank dynasties. Federico d'Aragona, on the other hand, was the son of the only king in the Italian peninsula and of the ruler with whom Charles the Bold had made his first Italian alliance; and though he was only the second of Ferrante's four legitimate sons, he did himself eventually succeed to the Neapolitan throne. Francesco d'Este arrived at the Burgundian court in 1444 and actually made it his home for over thirty years, until at least the middle of 1476. By contrast, Rodolfo Gonzaga stayed just over a year, from September 1469 until November 1470, while Federico d'Aragona, though he was two years away from Naples, spent a mere nine months with Charles. His purpose was almost entirely political, for he hoped to marry the duke's heiress Mary. Rodolfo's, on the other hand, was mainly a courtesy visit designed to cement the amicable relations already existing between Burgundy and Mantua rather than to achieve any specific diplomatic objective.