Leonardo da Vinci sketched an armored tank, a conical military vehicle with sloping armor and cannon openings.
His drawing, usually dated to around 1487–1489, shows a covered platform shaped somewhat like a truncated cone. Several cannons project through openings around its perimeter, while wheels and internal mechanisms were intended to move the vehicle. The design was apparently meant to protect soldiers while allowing them to fire in many directions.
The vehicle is often described as a predecessor of the modern tank, but it was never built or used in battle. Its proposed movement system has a famous problem: the gears as commonly drawn would make the wheels turn in opposite directions. Some historians think this may have been an intentional error because Leonardo was working for Ludovico Sforza and may have concealed part of the design.
Unlike twentieth-century tanks, Leonardo’s vehicle had no rotating turret, engine, or tracked wheels. It is more accurately understood as an imaginative armored fighting vehicle from the Renaissance.