This study investigates Giovanni Boccaccio’s role in the creation of the first Italian literary canon—that of Dante, Petrarca, and Boccaccio—between 1327 and 1366, during a period of intellectual experimentation reflected in Boccaccio’s literary and manuscript production. In the three chapters of this dissertation, through the lens of medieval theory of authorship, I examine how Boccaccio’s lifelong cultural project takes its shape in three fundamental manuscripts: Pluteo 29.8+33.31, Toledo 104.6, and Chigi L.V.176+L.VI.213. In chapter 1, I analyze Boccaccio’s writing practices in MS Pluteo (1327-1360) and describe its material layout (organization of text, decoration, type of writing). I question the pertinence of traditional definitions used to label this manuscript, and I argue instead for a hybrid categorization. In chapter 2, I study the content of MS Pluteo, and in particular of the last section of the manuscript that contains texts by Dante, Petrarca, and Boccaccio, using textual analysis not only to investigate Boccaccio’s material choices but also to define Boccaccio’s criteria behind the organization of his manuscript. Finally, chapter 3 provides a comparative analysis of MSS Pluteo, Toledo (1350-1355), and Chigi (1360-1366), examining the material and textual relationship between the three, and tracing the evolution of Boccaccio’s original project of an anthology of Dante and Petrarca. This study identifies for the first time MS Pluteo as the exemplar that anticipates Boccaccio’s later anthologies (Toledo, Chigi), thus dating back Boccaccio’s cultural project involving Dante and Petrarca to a decade earlier than is commonly accepted (1340). The analysis of these three manuscripts is also aimed at showing how Boccaccio read the works of his models, Dante and Petrarca, and how he established their importance for the Italian literary canon by demonstrating how his writing and material choices determined, since its earliest stages, the meaning of his literary project, and, consequently, of the direction the Italian literary and cultural tradition assumed with Boccaccio.