Francesco Melzi is known for creating the Codex Urbinas, which is a selection and careful compilation of Leonardo's thousands of pages of notes and sketches under the title "On Painting", and was later known as the Tratatto della Pittura (Treatise on Painting).[1] Although today we would not have the many manuscript copies and versions of Leonardo's notes and sketches if it weren't for Francesco's initial efforts, we can also attribute the loss of much of Leonardo's genius to Francesco. Once he inherited Leonardo's manuscripts, he extensively catalogued them and most likely had the intention to publish them.