Volley gun
The Ribauldequin was a medieval version of the volley gun. It had its barrels set up in parallel. This early version was first employed during the Hundred Years' War by the army of Edward III of England, in 1339. Later on, the late Swiss army employed it.
Volley gun
A volley gun is a gun with several barrels for firing a number of shots, either simultaneously or in succession. They differ from modern machine guns in that they lack automatic loading and automatic fire and are limited by the number of barrels bundled together.