Leonardo da Vinci designed a tank-like battlefield vehicle with conical armor.
Leonardo sketched the vehicle in the late 15th century, probably around 1487–1490, while working for Ludovico Sforza in Milan. Its sloping wooden covering was intended to deflect incoming attacks, while its shape gave the vehicle a low, fortified profile.
The vehicle was supposed to move using several cranks connected to wheels. A crew inside would operate the mechanism, although the design as drawn would not work properly because of a gearing error. Modern reconstructions commonly correct that error.
Leonardo’s design was not a modern engine-powered tank and was never built for battle in his lifetime. It is best understood as an armored fighting vehicle concept, centuries before tanks appeared in warfare during the First World War.