This thesis explores the way in which René, French prince and exiled king of Naples (1409-80), sought, by means of his transnational network of agents and allies, to assert his Italian political agenda chiefly through a programme of cultural politics. It is a case study for a ‘diplomatic’ approach to culture, and provides a new take on mid-fifteenth-century Italian politics as well. René of Anjou was defeated in a war for Naples in 1442 by Alfonso V of Aragon, but he maintained his Italian connections in the hopes of a return to the throne. His Italian network was based on the once-powerful Guelph faction, and then also on his chivalric Ordre du Croissant, which counted amongst its members the mercenary captain and usurping duke of Milan, Francesco Sforza. A programme of cultural politics, sometimes involving the exchange of gifts, other times simply involving politically-affective language, was part of keeping this network together. It was at the heart of the relationship between King René and Jacopo Antonio Marcello, a Venetian patrician and Croissant knight who brokered René’s connection to a number of major Italian cultural figures: Giovanni Bellini, Guarino of Verona, Andrea Mantegna, and Janus Pannonius, among others. The works they produced were crucial to the development and aggrandizement of the network, which was the foundation of a power bloc intended to return René to power in Naples. René tried to exploit this network in the Lombard wars of the early 1450s, but the Italian League that emerged in 1454 actually worked against René and his Guelph allies, particularly those in Florence who posed a threat to the Medici regime. After René’s ultimate military failure in the 1458-64 Neapolitan war of succession, his network evolved into a faction opposed to the Italian League and the state system it sustained.

Sous l’égide de Cosme l’Ancien puis de Pierre le Goutteux et de Laurent le Magnifique, la Florence médicéenne entretient avec l’Orient, et l’empire ottoman en particulier, une relation toujours plus étroite et plus ambiguë au fil du XVème siècle : c’est tout ensemble le séduisant ennemi et le modèle redoutable, fascinant par son exotisme et sa puissance. Le sultan et son Orient attirent les Florentins, subjugués par la différence de culture et l’ampleur des possibilités commerciales que propose le monde ottoman. Où se situe donc Florence, entre volonté de se poser en gardienne de la chrétienté, donc fermement opposée à l’onde déferlante des janissaires, et attirance naturelle pour un pays riche et raffiné ? Quellesconséquences a la relation de la ville du lys avec le Grand Turc sur l’Europe du XVème siècle ? Ce travail se propose de donner un éclairage des liens qu’entretient Florence avec le monde oriental, chrétien ou mulsulman, tout au long du XVème siècle, de l’avènement de Cosme en 1434 jusqu’à la mort de son petit-fils Laurent en 1492 : suivant une parabole chronologique et suivant les aléas des relations culturelles et diplomatiques, selon une connaissance qui se fait plus directe, Florence se présente tour à tour comme le rempart des chrétiens orientaux menacés par l’expansion de l’empire de Mehmet II, puis comme leur patrie d’accueil ouverte à la leçon grecque et enfin comme l’alliée de ce puissant seigneur, dont toute l’Europe reconnaît de fait la puissance redoutable. / Under the rule of Cosimo the Elder then Piero the Gouty and Lorenzo the Magnificent, the Florence of the Medici throughout the fifteenth century maintained increasingly tighter and more ambiguous relationships with the Eastern Ottoman empire which appeared both an attractive enemy and a formidable model with its fascinating exoticism and power. The Turkish civilisation attracted the Florentines dazzled by the different culture and the huge commercial possibilities it offered. What was then the real position of Florence caught between its wish to stand as the bulwark of Christendom (and therefore staunchly opposed to the Eastern invasion) and its natural inclination for a rich, refined country? What was the impact of the links between Florence and the Oriental Empire on fifteenth century Europe? This study aims at explaining the relationships between Florence and the Oriental world from the coming into power of Cosimo in 1434 until the death of his grandson Lorenzo in 1492: according to the ups and downs of cultural and diplomatic relashionships, Florence appeared one moment as the protection of the Oriental Christians threatened by the expansion of Mehmet II’s empire and the next as an alternative to their mother country by integrating Greek elements and compromising with the Sultan’s power, to eventually become the unofficial ally of the powerful emperor feared by all European states. / Sotto il dominio di Cosimo il Vecchio, di Piero il Gottoso e di Lorenzo il Magnifico, la Firenze medicea mantiene con l’Oriente, e più particolarmente con l’impero ottomano, una relazione sempre più stretta e più ambigua lungo il XV secolo : è, nello stesso tempo, il nemico seducente e il modello terrificante, affascinante col suo esotismo e la sua potenza. Il Sultano e la sua civiltà attraggono i Fiorentini, soggiogati dalla differenza di cultura e dalle immense possibilità commerciali che il mondo ottomano propone. Come si situa dunque Firenze, tra la volontà di proporsi quale baluardo della cristianità, quindi saldamente opposta all’invasione dei gianizzeri, e il fascino naturale nei confronti di un paese ricco e raffinato ? Quali conseguenze avrà la relazione della città del giglio e del Gran Turco sull’Europa del Quattrocento ? Questo studio propone una messa in luce dei legami che Firenze mantenne con l’Oriente lungo tutto il XV secolo, ovvero dall’avento di Cosimo nel 1434 fino alla morte del nipote Lorenzo nel 1492 : seguendo una parabola cronologica e a seconda degli eventi culturali e diplomatici, con una conoscenza che diventa sempre più diretta, Firenze si atteggia prima come baluardo dei cristiani orientali minacciati dall’espansione dell’impero di Maometto II, quindi come un’alternativa alla loro patria d’origine con l’integrazione della lezione greca da una parte e dall’altra con l’affermazione della potenza del sultano, e infine come l’alleata inconfessabile di questo signore, la cui potenza è riverita in tutta Europa.