Ayer MS 743: New Light on a Greek Manuscript of Ptolemy’s Geography in Chicago

Recent research on the only Greek manuscript of Ptolemy’s Geography in America, Ayer MS 743 (Newberry Library, Chicago, identical with Codex Romanus Monasterii Sancti Gregorii in monte Coelio 15 which until recently was thought to be lost) reveals that it was copied for the famous humanist Francesco Barbaro in Venice by two Byzantine scribes working for him in the 1410s. The manuscript is therefore the oldest extant document testifying to the presence of Ptolemy’s Geography in Venice. Its unusual and complicated structure provides insight into the beginnings of the transmission of the Geography in Western Europe. Later on, Ayer MS 743 belonged to Francesco’s grandson Ermolao and to the library of the Venetian monastery San Michele di Murano before moving to Rome, London, and finally Chicago.