Here he made the acquaintance of the famous Benedictine scholar Bernard de Montfaucon, at the time traveling in Italy in search of manuscripts for his edition of the works of St. John Chrysostom.

Banduri rendered him valuable services and in return was recommended to Cosimo III de' Medici, Grand Duke of Tuscany for the chair of ecclesiastical history in the University of Pavia.

In 1711 he published at Paris his De Administrando Imperio (Imperium Orientale, sive Antiquitates Constantinopolitanae), a documentary illustrated work on the Byzantine Empire, based on medieval Greek manuscripts, some of which were then first made known.

In 1718 he published, also at Paris, two folio volumes on the imperial coinage from Trajan Decius to the last of the Palaeologi (249-1453), Numismata Imperatorum Romanorum a Trajano Decio usque ad Palaeologos Augustos (supplement by Tanini, Rome, 1791).

In 1715 Banduri was made an honorary foreign member of the Académie des Inscriptions, and in 1724 was appointed librarian to the Duke of Orléans; he had in vain solicited a similar office at Florence on the death of the famous Antonio Magliabechi.