Leonardo da Vinci sketched an armored tank in 1487 as a mobile fighting machine.
His design used a conical, turtle-like shell made from wooden plates reinforced with metal. Sloping armor was intended to deflect incoming weapons, while a ring of cannons around the vehicle offered all-direction fire. The machine was powered by men turning internal cranks connected to wheels.
The drawing appears in Leonardo's notebooks and is generally treated as a concept rather than a completed vehicle. A famous detail is that the original mechanism seems unable to move because some gears are arranged incorrectly. Historians often interpret that flaw as deliberate concealment, an error, or an unfinished design.
It is usually called Leonardo's tank or fighting vehicle, but it was not a modern tank: it had no engine, tracks, turret, or enclosed crew compartment. Its importance lies in combining armor, mobility, and concentrated fire centuries before practical tanks appeared.