Recto: drawings of machinery and geometric diagrams; studies of horses; studies of nude men, standing and in motion; heads in profile; a larger drawing of an angel. Verso: studies of prancing horses; a classical profile; a ratchet and two diagrams. The lower corners of the sheet are cut. Melzi's number 53. Leonardo’s most ambitious painting was the Battle of Anghiari, a huge mural commissioned by the Florentine government for the Great Council Chamber of the Palazzo della Signoria. It remained unfinished when Leonardo was called back to Milan in 1506, and was obliterated fifty years later. Here Leonardo sketches ideas for the composition – warriors standing or pole-vaulting across a gulley, and horses galloping, rearing and kicking. In the note at lower centre Leonardo jots down a memorandum to ‘make a small one in wax, one finger long’, strongly suggesting that he developed the complex mural by modelling small figures. The Angel of the Annunciation in black chalk is a pupil’s drawing, corrected by Leonardo with pen lines. Text adapted from Leonardo da Vinci: A life in drawing, London, 2018