What mechanical animal did Leonardo da Vinci build for a 1515 royal celebration in Lyon?

Leonardo da Vinci built a mechanical lion for a royal celebration in Lyon in 1515.

The lion was created for the meeting of King Francis I of France and Pope Leo X, according to accounts of Leonardo’s final years in France. It reportedly walked forward and opened its chest, revealing fleurs-de-lis, the emblem associated with the French monarchy. The display presented mechanical movement as courtly spectacle.

The original machine has not survived, so details of its construction are known through historical descriptions and later reconstructions. It was not a programmable robot in the modern electronic sense. Its movements would have depended on mechanical parts such as gears, cams, springs, or concealed operators.

The lion is often grouped with Leonardo’s mechanical inventions because it demonstrates his skill in automata and theatrical engineering. It should not be confused with Leonardo’s earlier humanoid robot design, which is based on a separate set of drawings and was reconstructed centuries later.