What military vehicle did Leonardo da Vinci sketch in 1487 with conical armor and cannons?

Leonardo da Vinci sketched an armored fighting vehicle in 1487 with conical armor and cannons.

The vehicle was intended to move using cranks connected to wheels. Its sloped covering was designed to deflect enemy fire, while several light cannons projected through openings around the platform. The design resembles a tank, although it was never built or tested in Leonardo’s lifetime.

The surviving drawing appears in the Codex Arundel and is often called Leonardo’s tank. Modern reconstructions have noted that the gearing shown in the sketch may prevent the wheels from turning correctly. Some historians interpret that mismatch as an error, while others suggest it may have been deliberate to keep the design from being copied.

Leonardo’s concept belongs to Renaissance military engineering rather than modern armored-vehicle development. It had no engine, enclosed crew compartment, or proven battlefield performance.