What type of armored machine did Leonardo da Vinci sketch for warfare?

Leonardo da Vinci sketched an armored vehicle, an early tank-like machine intended for warfare.

His design, usually dated to the late fifteenth century, resembles a conical, turtle-shaped covered wagon. Sloped armor was intended to deflect incoming projectiles, while several light cannons projected through openings around the vehicle. Internal crew members would turn cranks connected to the wheels.

The machine was never built for Leonardo's patron, Ludovico Sforza, and no evidence shows that it entered combat. A famous modern claim says Leonardo deliberately included a gearing error to prevent the design from being used, but historians treat that interpretation cautiously; the apparent problem may instead reflect a drawing or reconstruction issue.

Calling it a modern tank is convenient but anachronistic. It lacked an engine, modern suspension, and a practical crew layout, so “armored vehicle” is the more historically careful description.