The thesis, which aims to study the lexicon of public institutions in the town chronicles composed in Venice between the end of the 13th and the end of the 14th century, is organised in two parts. In the first one, the chronological corpus of the 14th century, in Latin, Venetian vernacular and Old French, is examined from an textual perspective, paying particular attention to Andrea Dandolo's Chronica Brevis and its vernacular translation, here named α, of which a linguistic study is also offered, which form the basis of the remaining production: the Cronica de tuta la provença della citade de Veniexia, of which the second chapter offers the first findings on the tradition and a study of the sources, and the other numerous Latin and vernacular chronicles, anonymous or authorial, from the second half of the 14th century, and Martin da Canal's Estoires de Venise, a 13th-century work, unicum of the corpus, which is used a lot for the following production, which are presented more briefly in the third chapter. On the basis of the conclusions of the first part, the second is thus dedicated to the analysis of the lexicon of institutions and the exercise of power through a lexicological chapter that aims to show the specificities of this lexical system and a lexicographical one that includes a glossary of ninety significant entries, in which the semantic values of the different lexemes are studied, starting from Venetian vernacular and extending to Latin and Old French. The thesis closes with four appendices: the lemmary and the transcriptions of the two manuscripts of α and the chronicle of ms. Hamilton 196 of the Staatsbibliothek in Berlin.