Cannons Primitive cannons used at siege of Metz. Metal cannonballs flung with gunpowder far more destructive than catapults. Edward III England 1346 Cannons Primitive cannons used at siege of Metz. Metal cannonballs flung with gunpowder far more destructive than catapults. Built on CatapultGunpowder Led to ArtilleryMexico conqueredPeru conquered