Leonardo da Vinci designed an armored vehicle with a conical body and internal gears in 1487.
The vehicle appears in a design associated with Leonardo’s work for Ludovico Sforza, Duke of Milan. Its sloped armor was intended to deflect attacks, while several cannons protruded around the circular platform. Inside, crews would turn cranks connected to the wheels through gearing.
The machine is often described as an early tank, but that label can mislead. Leonardo’s vehicle was not powered by an engine, and the surviving design has a gearing problem that would make the wheels turn in opposing directions. Some historians have suggested that the apparent flaw may have resulted from an intentional concealment or a drafting error, but its exact purpose remains uncertain.
A modern reconstruction demonstrated that the general concept could be built, though it required changes to the mechanism. The design is therefore best treated as an armored fighting-vehicle concept, not a functioning Renaissance tank.