Fifteenth-century diplomatic protocol required the city of Florence to send diplomats to congratulate both new and militarily victorious rulers. Diplomats on such missions poured praise on their triumphant allies and new rulers at friendly locations. However, political realities also meant that these diplomats would sometimes have to praise rulers whose accession or victory opposed Florentine interests. Moreover, different allies and enemies required different levels of praise. Jealous rulers compared the gifts, status, and oratory that they received from Florence to the Florentine entourages sent to their neighbors. Sending diplomats with too little or too much social status and eloquence could spell diplomatic disaster. Diplomats met these challenges by varying the style, structure, and content of their speeches. Far from formulaic pronouncements of goodwill, diplomatic orations varied from one speech to the next in order to meet the demands of the complex diplomatic world into which they fit. Contextualizing these orations reveals the subtle reservations of diplomats praising a hostile ruler, the insertion of specific citations to flatter specific audiences, and the changing intellectual and stylistic interests of humanists throughout the fifteenth century. This essay will examine the different shades of flattery practiced by Florentine diplomats and the contexts that explain these variations.

Prenant appui sur une historicisation critique des postulats méthodologiques et idéologiques au fondement des catégories d’humanisme civique et de républicanisme, la thèse entend renoncer à une lecture uniquement théorique de l’œuvre des humanistes florentins et restituer aux textes leur statut d’énoncés historiques. L’enjeu est de redessiner les lignes portantes d’une tradition civile et républicaine propre à la réalité florentine dont les penseurs des guerres d’Italie (Savonarole, Guichardin, Machiavel) seront les dépositaires critiques. Un travail d’interprétation de la correspondance familière de Coluccio Salutati (1331-1406) constitue le socle de la recherche et fait apparaître la dimension juridique de la pensée du chancelier, et ce à double titre : d’une part elle révèle l’omniprésence d’un lexique juridique qui fournit l’essentiel de l’arsenal interprétatif de l’analyse politique, et d’autre part, elle définit un « office d’exhortation » qui constitue la théorie politique de Salutati non pas simplement comme une rhétorique propagandiste mais aussi comme un discours réformateur. L’apport de Leonardo Bruni (1370-1444) est ainsi réévalué dans le sillage de l’humanisme politique de Salutati, et se distingue de ce dernier surtout par la valeur nouvelle accordée à l’histoire dans l’élaboration d’une langue et d’une science de la vie civile. / Starting from a critical historicization of the methodological and ideological foundations of categories such as civic humanism and republicanism, this thesis investigates the works of the Florentine humanists not only from the point of view of political theory but also in relation to their historical significance. The aim is to redefine the structural lines of a republican tradition characteristic of Florentine history, a tradition which the thinkers of the Italian Wars (Savonarola, Guicciardini, Machiavelli) inherited and criticized. An extensive reading of the private letters by Coluccio Salutati (1331-1406) constitutes the central part of this work and reveals the juridical character of the Chancellor’s thought : on the one hand, the juridical vocabulary is omnipresent in the letters and provides the core of the hermeneutic tools necessary to political analysis ; on the other hand, it helps defining an « office of exhortation » which discloses Salutati’s urge for reform rather than his role of propagandist. New light is then shed on Leonardo Bruni’s contribution to political thought as Bruni is seen following the path of Salutati’s political humanism. Leonardo Bruni (1370-1444), in comparison with his master, stresses the superiority of history, but finds himself equally involved in the formulation of a language and a science of political life.