The Manuscripts of Leonardo da Vinci

This Mazzenta Ambrogio Mazzenta (1559–1635), a Barnabite monk and early chronicler of the manuscripts, who was studying law in Pisa, met Lelio Gavardi d’Isola there, the tutor to the children of Horatio Melzi. This unworthy son Horatio was the son of Francesco Melzi, Leonardo's loyal pupil had put the drawings, books, and works of Leonardo in the attic in old crates. The tutor managed to get thirteen manuscripts given to him, which he hoped to sell to the Grand Duke Francesco; the latter died, and Gavardi d’Isola came to Pisa to study law under his relative Aldus Manutius The younger Aldus Manutius, of the famous Venetian printing family.

The Mazzenta of this account made Gavardi feel ashamed for having appropriated such precious things; he spoke so persuasively that the aforementioned Gavardi charged him with returning everything to Horatio Melzi.

"The latter was astonished and made me a gift of the manuscripts, saying that for many years there had been many drawings by the same author in the rooms of his villa, under roofs in poor condition."

Mazzenta’s brothers boasted of what they possessed, and many people asked Horatio Melzi for drawings and pages by Leonardo; among them was Pompeo Aretino, the knight Leone Pompeo Leoni (c. 1533–1608), a sculptor and collector who served the Spanish court. The latter promised Horatio Melzi a seat in the Senate of Milan if he recovered the thirteen manuscripts; Sebastiano One of the Mazzenta brothers was made to return seven of them by the Mazzentas, who kept six for themselves.

One was given to Cardinal Borromeo (the Treatise on Light and Shadow, now at the Ambrosiana The Biblioteca Ambrosiana in Milan); the second to the painter Figgini; the third to Duke Emmanuel of Savoy; the other three fell to Pompeo Aretino, who made them into a large book (Codex Atlanticus The largest collection of Leonardo's papers, so named for its atlas-like size). His heir Calchi sold it to Arconati for 300 crowns.