Leonardo da Vinci designed an armored vehicle as a covered, conical fighting machine with cannons around its sides.
The vehicle appears in a drawing from about 1487 to 1489. Its sloping, turtle-like shell was intended to protect occupants, while multiple light cannons projected through openings around the perimeter. The machine was to move using wheels turned by internal cranks and gears.
Leonardo proposed the vehicle for military use, probably while seeking patronage from Ludovico Sforza in Milan. The design was never built as a battlefield machine in Leonardo’s lifetime. Its armor, large number of guns, and unusual shape made it visually impressive, but its actual mobility and steering would have created major engineering problems.
Some modern retellings claim Leonardo deliberately inserted a flaw into the gearing. That idea is not securely established by the historical evidence. The safest description is that the drawing presents an armored fighting vehicle concept, not a proven tank or an operational weapon.