Leonardo da Vinci designed an organ gun with 33 gun barrels arranged in three rows.
The weapon was intended to fire a large number of small guns in sequence or together. Its nickname comes from the visual and functional resemblance of the barrel arrangement to the pipes of a musical organ. The design used a wheeled frame so it could be moved and positioned on a battlefield.
The 33-barrel arrangement is often described as a precursor to the modern multiple-barrel machine gun, but that comparison should be made carefully. Leonardo’s weapon used separate gun barrels and black-powder firing technology, not a modern cartridge-fed mechanism. Like many of his military designs, it survives chiefly as a drawing and proposal rather than as a documented battlefield success.