What armored vehicle did Leonardo da Vinci sketch around 1487 for military use?

Leonardo da Vinci sketched an armored tank around 1487 for military use.

His design was a conical, turtle-shaped vehicle covered with armor plates. It was intended to carry several soldiers and move across a battlefield while protecting its crew from enemy fire. The vehicle had wheels driven by hand-operated cranks inside the hull.

The design was never built in Leonardo’s lifetime. A frequently discussed problem is that the gearing shown in some drawings would make the vehicle move backward rather than forward. Historians commonly interpret this as either a drafting error or a deliberate safeguard against unauthorized use.

Leonardo’s vehicle was not a modern tank: it had no engine, tracks, turret, or cannon in the modern sense. Its importance lies in combining armored protection, crewed transport, and offensive weapons in one early concept.