Leonardo da Vinci sketched an armored car with a conical shell and several cannons.
The vehicle appears in a drawing made around 1487 for Ludovico Sforza, Duke of Milan. Its sloped, turtle-like cover was intended to protect soldiers inside, while light cannons were arranged around the vehicle so they could fire in different directions. The design is commonly regarded as an early ancestor of the modern tank.
Leonardo’s drawing shows a crew turning cranks connected to the wheels. However, the gearing as drawn would make the vehicle difficult or impossible to drive forward, leading to the famous claim that he deliberately inserted a technical error. Historians cannot prove whether the flaw was intentional, accidental, or simply unresolved.
The armored car was never built as a Renaissance battlefield vehicle. It remained a design study, but its combination of armor, mobility, and all-around firepower made it one of Leonardo’s most famous military inventions.