Leonardo da Vinci sketched an armored vehicle with sloped protection and many small cannons.
The vehicle is often called Leonardo's fighting vehicle or tank. His drawing shows a covered, conical structure resembling a tortoise shell, with angled armor intended to deflect incoming projectiles. A ring of light cannons points outward through openings, allowing the crew to fire in multiple directions.
Inside, operators would turn cranks connected to gears and wheels. The machine was therefore powered by people rather than an engine. A famous flaw in the surviving design is that the gearing appears to make the vehicle move in the wrong direction if assembled exactly as drawn. Some historians think this may have been an intentional error, a drafting mistake, or an incomplete design.
It was never a battlefield tank and there is no evidence that Leonardo's patron put it into production. The “tank” label is a modern comparison: twentieth-century tanks used engines, tracks, and military systems unavailable in Leonardo's period.