The Archivio Storico Civico e Biblioteca Trivulziana came into being in 1935 following the incorporation of the Trivulzio collection into the pre-existing Archivio Storico Civico of Milan. Since then the Institute has been promoting, increasing and improving its collection of documents and books. Currently, the Institute preserves over 1.300 manuscripts, 1.300 incunabula, 16.000 16th century publications and over 180.000 printed editions, while the document collection extends to approximately 1280 metres in length. To support the study of the collection and general research, access is provided to up to date bibliographical catalogues, manuals on philology, linguistics, palaeography, the history of Milan and the history of printing. In addition, the Institute possesses an extensive collection of Italian and foreign journals, 150 of which are ongoing subscriptions.The Trivulziana’s most antique codex dates back to the 8th century while the library’s most famous possession is the autographed notebook of Leonardo da Vinci. Particularly noteworthy is also a collection of manuscripts comprising Dante’s texts, including a codex of the Divine Comedy dating to 1337 and a precious 14th century manuscript of the De Vulgari Eloquentia, while among the incunabula there is a complete collection of the 15th century editions of Dante’s Divine Comedy.