Leonardo da Vinci’s sloped-armored military vehicle was an armored tank. He designed a conical, turtle-like vehicle in the late 15th century, with armor plates and multiple small cannons arranged around its sides.
The vehicle was intended to move across a battlefield while protecting the crew. Its sloped armor could deflect projectiles, and the circular plan gave the crew a broad field of fire. Leonardo’s drawing shows space for men inside to operate the machine.
The design is sometimes described as a modern tank invented centuries early, but it was never built for Renaissance warfare. A frequently discussed problem is that the internal gears appear to be arranged so the vehicle could not move as drawn. Some historians suggest this may have been deliberate, either to conceal the design or because Leonardo had not solved its mechanical details.