A turtle inspired the armored vehicle Leonardo da Vinci designed for war.
Leonardo’s fighting vehicle, drawn in the late 15th century, had a conical armored shell that spread outward from a raised central platform. Its shape resembles a turtle’s domed body and was intended to protect soldiers inside from hostile weapons. The vehicle was to be moved by people turning cranks connected to wheels.
The design included numerous guns around its perimeter, allowing it to fire in several directions. Leonardo presented the concept in the context of military engineering while working for Ludovico Sforza in Milan, where he sought patronage by emphasizing his abilities as an engineer and weapons designer.
The vehicle was never built in Leonardo’s time. Modern discussions often call it a tank, but that term belongs to much later armored military vehicles. Some historians also note that the surviving drawing appears to contain a mechanical problem that would prevent the proposed cranks from working as intended.