Leonardo da Vinci designed an armored tank with sloped armor and guns arranged around its platform.
The vehicle appears in a drawing usually dated to about 1487–1488. Its conical, turtle-like shell was intended to protect occupants, while a circular arrangement of light cannons allowed fire in multiple directions. The design also included internal mechanisms connected to wheels, suggesting that a crew would propel it from inside.
It was a proposal rather than a battlefield vehicle. The surviving drawing contains a mechanical problem: the gearing, as shown, would make the wheels work against one another. Some historians interpret this as an error, while others have suggested that Leonardo may have deliberately concealed or altered part of the mechanism.
The machine is commonly called Leonardo’s tank, although it predates modern armored warfare by centuries and was never documented as having been built or used.