What is the Codex Magliabechiano?
The Anonimo Magliabechiano — also known as the Codex Magliabechiano, Codex Gaddiano or Codex Billi — is a 128-page manuscript containing biographies of important Renaissance artists, including Leonardo da Vinci and Michelangelo. Nothing is known about its author. The work is named after its former owners Antonio Magliabechi and Niccolò Gaddi; accordingly, in scholarship the author is referred to as the Anonimo Magliabechiano or Anonimo Gaddiano.
In older Leonardo biographies the Florentine merchant Antonio Billi, the first known owner of the manuscript, was still cited as its author. Whether he was in fact the writer is unclear. The text is generally dated to between 1542 and 1548.
The codex appears overall rather unstructured but is frequently cited — for example, to support the existence of a Leonardo painting with the subject of Adam and Eve or the attribution of the portrait of Ginevra de’ Benci to Leonardo. Because of content parallels, it has been debated whether Giorgio Vasari might be the author or whether it is at least a preliminary study for his Lives of the Most Excellent Italian Architects, Painters and Sculptors from Cimabue to Our Times. At the very least, it is likely that Vasari knew the codex and incorporated passages from it into his work.
In addition to Leonardo, the manuscript also contains a biography of Michelangelo. The two passages on Leonardo are reproduced below.