Ms. Auct. T. 5. 21 of the λ version of the Alexander Romance is precisely dated (1516) and offersthree notes which give us the name of one of its owners and readers, Cirillo Giustiniani, archbishopof Grevena. This article provides a new reading and a new interpretation of these notes, supported byfindings in the historical archives of the Congregazione per la Dottrina della Fede.