Leonardo da Vinci’s covered, conical military vehicle was an armored tank.
Leonardo sketched the fighting vehicle in the 1480s, probably while seeking employment from Ludovico Sforza, the Duke of Milan. Its sloping, conical cover was intended to deflect incoming weapons, and cannons were arranged around the vehicle so it could fire in multiple directions.
The design was powered by people turning cranks connected to wheels. Modern reconstructions have debated whether the original mechanism would work as drawn. Some have identified a possible gear arrangement that would prevent the wheels from turning correctly, although this may have been an intentional mistake to keep the design secret or an error in the sketch.
Leonardo’s vehicle was not a modern tank: it had no engine, tracked wheels, or battlefield record. It is best understood as a Renaissance armored fighting-vehicle concept. The nickname “Leonardo’s tank” comes from its protective shell and mobile artillery role.