On this sheet Leonardo makes studies for two separate paintings. The larger sketch of a rearing horse, with indications of a rider reaching down is a study for Leonardo’s most ambitious painting, the Battle of Anghiari. This huge mural of men and horses in violent action, depicting a celebrated Florentine victory over Milan, was commissioned in 1503 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. The smaller sketches are for a composition of Leda and the Swan. In classical mythology, Leda, queen of Sparta, was seduced by Jupiter in the form of a swan and bore two eggs, from each of which hatched twins. Here Leonardo shows Leda kneeling, her children gathered around her, but with no indication of the swan. Melzi's number 26.

Verso: mortars firing into a fortified area, with their trajectories shown; a cursory sketch of a man on horseback; some notes relating to the mortar diagram. Leonardo worked as a military engineer on several occasions, and considered writing a treatise on the subject. This design shows a method of bombarding a besieged fortress.

Text adapted from Leonardo da Vinci: A life in drawing, London, 2018