Leonardo da Vinci’s armored military vehicle design from around 1487 is commonly called Leonardo’s tank.
Leonardo sketched the vehicle as a covered, conical machine with sloping armor and multiple light cannons around its sides. Several men inside would turn cranks connected to gears, allowing the vehicle to move while protecting its crew from weapons fire.
The design appears in Leonardo’s notebooks, including the Codex Atlanticus. It was probably intended as a military engineering proposal rather than a machine that was actually built and used in battle. Modern writers often call it a tank because its shape and battlefield role resemble later armored vehicles, but the word “tank” belongs to twentieth-century military technology.
A famous drawing seems to show gears that would make the vehicle move backward. Historians commonly interpret this as a copying or calculation error, although some have suggested it could have been deliberate sabotage in a design intended for military patrons.