The longest list of books was compiled between 1503 and 1504, in Florence, perhaps on the occasion of a trip. The list is in fact headed with the rubrics “Ricordo de’ libri ch’io lascio serrati nel cassone” (Record of the books I keep locked in the large chest) and “in cassa al munisterio” (in the chest at the monastery) – perhaps the convent of Santa Maria Novella, where Leonardo worked on the cartoons of the Battle of Anghiari. The list (comprising 116 volumes) testifies to the broadening of Leonardo’s intellectual horizons, which saw a significant increase in the books on the shelves dedicated to philosophy, science and technology.