What Leonardo da Vinci invention was a humanoid machine designed to sit, wave, and move its arms?

Leonardo da Vinci designed a humanoid machine known as Leonardo's robotic knight.

Leonardo created the design in Milan around 1495 for a pageant celebrating the marriage of Ludovico Sforza. The machine was apparently intended to sit, stand, move its arms, and raise its visor. Its movements came from a system of cables, pulleys, and gears operated by an internal mechanism.

The design appears in Leonardo's notebooks, but no original robot survives. In 2002, roboticist Mark Rosheim built a working interpretation based on Leonardo's drawings. Later reconstructions showed that the mechanism could perform several of the motions Leonardo sketched.

The robotic knight is often called Leonardo's robot, but it was not a programmable electronic robot. It was a Renaissance mechanical automaton, designed centuries before modern robotics and computers.