What humanoid automaton did Leonardo da Vinci design in armor around 1495?

Leonardo da Vinci designed a humanoid automaton in armor around 1495, known as the mechanical knight.

The design was prepared for a pageant in Milan under the patronage of Ludovico Sforza. Leonardo’s notes and drawings indicate a figure enclosed in Italian-Germanic armor and powered by a system of gears, cables, and pulleys. The mechanisms were intended to produce humanlike actions such as sitting, standing, and moving the arms.

No original mechanical knight has survived, and the surviving evidence is incomplete. In the twentieth century, researchers located relevant drawings in the Codex Atlanticus and built reconstructions based on them. Those reconstructions showed that a functioning automaton was mechanically plausible, but they do not prove that Leonardo completed the exact figure described in every modern account.

The knight is sometimes called Leonardo’s robot. That is a useful modern comparison, but it should not imply electronics or artificial intelligence. The design was a Renaissance mechanical automaton, operated by physical linkages and stored mechanical energy.