What mechanical animal did Leonardo da Vinci create for a French royal celebration in 1515?

Leonardo da Vinci created a mechanical lion for a French royal celebration in 1515.

The lion was an automaton, meaning a machine designed to move or perform an action through internal mechanisms. Historical accounts connect it with Leonardo’s work for King Francis I of France. The animal reportedly walked into a ceremony and opened its chest to reveal fleurs-de-lis, the heraldic symbol associated with the French monarchy.

The machine was a spectacular piece of court entertainment as well as an engineering demonstration. Leonardo had studied animal anatomy and movement, and an automaton shaped like a lion allowed him to combine those interests with gears, linkages, and theatrical presentation.

The original mechanism has not survived, and accounts differ on some details of its construction and performance. That is why modern reconstructions are based on historical descriptions and related drawings rather than a complete surviving machine. The lion was not a robot in the modern electronic sense; it was a Renaissance mechanical automaton.