Leonardo da Vinci sketched an armored tank as a conical, armored military vehicle powered by internal wheels.
The design appears in Leonardo’s studies from around 1487–1488, probably made while he was seeking employment from Ludovico Sforza, Duke of Milan. Its sloping shell was intended to deflect enemy fire, while several crew members inside would turn cranks connected to the wheels.
The vehicle was never built in Leonardo’s lifetime, and it was not a modern tank with an engine, tracks, or a turret. It was a theoretical fighting machine that combined a protected crew compartment with mobile artillery. Some modern reconstructions have noted that the surviving drawing appears to contain a gear arrangement that would prevent the wheels from turning in the intended direction; this may have been an error, a deliberate safeguard, or a later alteration.
The design is commonly called Leonardo’s fighting vehicle, but “armored tank” is the familiar modern description of the concept.