Leonardo da Vinci designed an organ gun, a weapon with many small cannons arranged on one platform.
The weapon’s name comes from the visual resemblance between its parallel barrels and the pipes of a musical organ. Leonardo’s version, sometimes called a 33-barrel organ, arranged multiple guns in rows on a wheeled frame. The layout was intended to let crews fire a concentrated volley and then reload another row.
This was not a machine gun in the modern sense. The barrels were separate muzzle-loading guns, so the weapon could not deliver continuous automatic fire. Its practical rate of fire would depend on loading, aiming, and the crew. Leonardo included the design among his military engineering studies, which also covered fortified structures, artillery, and armored vehicles.
Organ guns existed in different forms before and after Leonardo. Therefore, the most precise answer is organ gun, not “the first machine gun.” Leonardo’s drawing is important because it shows how he applied coordinated barrel arrangement to battlefield firepower.