Leonardo da Vinci sketched an armored tank as a conical, covered military vehicle carrying cannons around its base.
The design appears in Leonardo’s notebooks from the late fifteenth century, when Italian city-states frequently fought using artillery, fortifications, and mercenary armies. Its sloping outer shell was intended to deflect incoming projectiles, while the guns could fire in several directions.
The vehicle was meant to be moved by people turning cranks connected to wheels. A commonly repeated story says the design was deliberately made impossible by reversing some gears, perhaps so Leonardo could protect the idea from unauthorized use. Historians debate whether that error was intentional.
It was not a modern tank: it had no engine, tracks, or proven battlefield prototype. The concept is nevertheless often described as an early tank because it combined armored protection, mobility, and mounted artillery in one vehicle.