In the mid-1480s Ludovico Sforza, ruler of Milan, commissioned Leonardo to make a huge bronze equestrian monument to his father Francesco. The first designs show the horse rearing, but around 1490 this was changed to a less ambitious walking pose. Leonardo then studied the form of the horse intensively, making drawings both in casual poses and in strict orthogonal views, from the side and from the front.

Leonardo built a clay model of the horse, well over life size, and constructed a mould and foundry for the casting. But in 1494 the 75 tons of bronze assembled to make the cast was requisitioned to make cannon, and the project was suspended.

Five years later French forces took Milan and deposed Ludovico Sforza. Leonardo’s clay model for the horse was used for target practice by the French troops and destroyed. Leonardo recorded laconically in his notebook, ‘the Duke lost his state, his property and his liberty, and none of his works was finished.’