At the request of Ludovico Sforza, the future Duke of Milan, Leonardo da Vinci began working on a sculpture that would be the largest equestrian statue in the world in 1482. Leonardo made sketches of the horses in the Sforza stables, from which he designed a 24-foot-high clay model.
Leonardo wanted to cast the horse in a single operation and designed elaborate plaster molds to make that possible. In his innovative process, the inverted molds would be buried between two ovens, and molten bronze would fill them to cast the statue.
The plans were set to create the giant horse, but war with France engulfed Milan in 1499. Sforza needed the bronze for weapons, not art, and the materials were diverted to forge cannons. The French defeated Milan, occupied Sforza's lands, and destroyed the clay horse. Leonardo’s drawings and plans survived, but the artist died in May 1519 before “Il Gran Cavallo” could be brought to life.