The ruler of Florence sent Leonardo to Milan in 1482 bearing a silver lute as a gift to the powerful and warlike ruler of Milan, Duke Lodovico Sforza. Leonardo was by then known as a talented musician as well as a skilled painter and sculptor.

Leonardo wrote an amazing letter to Duke Sforza. The letter described many of Leonardo's fascinating and original ideas for military engineering. He wrote how he could build strong light bridges, create fantastic new weapons, and build armored chariots and warships to protect the Duke's soldiers in battle. Only at the end of this letter did Leonardo describe his talents as a sculptor and painter and offer to create a bronze horse statue to honor the Duke's father. Sforza was impressed by Leonardo and gave gave him a position at court as painter and engineer.

Leonardo was kept busy in Milan. He established a studio and had apprentices of his own. He planned the costumes and sets for festivals and plays, designed and built forts, laid out new canals for the city and painted many portraits. Leonardo also worked on his great painting,The Last Supper. Unfortunately, only a shadow of the original masterpiece remains. Leonardo used an experimental mixture of tempera and oil paints which did not stick well to the damp plaster wall. Soon after the painting was completed in 1498, the paint began to flake away.

At the same time as he was painting The Last Supper , Leonardo designed and constructed a full sized clay model for a 24 foot high statue of the Duke's father on horseback.

In 1499 before the statue could be cast in bronze, Milan was attacked and overrun by the French troops. Duke Sforza's family fled, and French archers destroyed the gigantic clay horse while using it for target practice.

The French governor of Milan, Charles d'Amboise, invited Leonardo back to Milan in 1506. King Louis XII of France, living in Milan at the time, appointed Leonardo court painter one year later. Leonardo continued to work on engineering projects in Milan. He also had time to continue his scientific studies of geology and anatomy, both human and animal, and to study astronomy. When the French governor of Milan died in 1511, political changes forced Leonardo to leave the city once again.