What humanoid machine did Leonardo da Vinci design in armor for a Milanese court display?

Leonardo da Vinci designed a humanoid machine in armor known as the mechanical knight.

Leonardo prepared the design around 1495 for a pageant at the court of Ludovico Sforza in Milan. Inside an armor shell, a system of pulleys, cables, and gears could make the figure sit, stand, raise its arms, and move its visor. The mechanism translated the motion of a smaller internal frame into the movement of the armored exterior.

No original mechanical knight has survived, so the exact performance of Leonardo’s machine is uncertain. In 2002, roboticist Mark Rosheim built a working reconstruction based on Leonardo’s drawings and notes. The reconstruction helped show that the design was mechanically plausible. It is often called Leonardo’s robot, but “robot” is a modern label; the more historically precise description is an automaton or mechanical knight.