Leonardo da Vinci designed an armored tank powered by soldiers turning cranks.
His fighting vehicle was drawn around 1487–1488 while he was seeking military work from Ludovico Sforza in Milan. The machine had a conical, armored shell inspired partly by a tortoise. It was intended to move across a battlefield and provide protection for the soldiers inside while they fired weapons through openings.
The vehicle would have been driven by internal cranks connected to wheels. Some modern analyses note that the gearing shown in the surviving drawing appears problematic, possibly preventing the vehicle from moving as intended. Historians debate whether this was a deliberate safeguard or simply an engineering error.
It was a concept, not a documented operational tank. Modern armored tanks use engines, tracks or wheels, armor, and mounted weapons, but Leonardo’s design is remembered as an early attempt to combine battlefield mobility and protection.