Gunpowder rockets were used in warfare in Asia from the early 11th century. There was also experimentation with bamboo-tube gunpowder weapons. By the 13th century the Chinese developed metal tubes that lay fair claim to be the first gunpowder cannon.
The first references to gunpowder artillery in Europe are to ”pots de fer” (”fire pots”). These were small, vase-like, bellshaped pieces. That was important: the long-term lead Europe eventually took in casting artillery was partly rooted in the skills of bell-makers used to casting bronze bells to fill the huge demand from churches. Because ”pots de fer” were fired from the ground rather than a stabilizing gun carriage they were wildly inaccurate. Also, illustrations suggest they shot thick arrows, wrapped in leather to better fit the mouth of the vase and seal in propellant gasses, not stone or metal balls.
They were so ineffective they often did little or no damage to the enemy beyond making a frightful noise and belching fire and smoke to befuddle superstitious troops unused to such daemonic devices and artificial cacophonies. However, this effect cannot have lasted long once it was noticed that no one was actually hurt. Such primitive cannon posed more danger to their own side than to the enemy: a cracked or flawed bell would allow expanding gases to explode the casing into shrapnel, killing or wounding anyone nearby. Or a mishandled match might set off spare powder to scorch, sear, and blind the crew. As late as 1460 a defective cannon exploded at Roxburgh and killed the Scottish king, James II (1437-1460).
As barrels were made tubular, longer, and thicker, it was common practice to affix the gun to a thick board; this allowed adjustments to be made to the angle of fire (which remained line-of-sight only) by adding or decreasing the earth rampart on which the whole contraption rested. Only much later were gun carriages made. The first recognizable, tubular cannon of which there is a record appeared in Florence in 1314. Twelve years later guns capable of firing iron balls were certainly ordered for the defense of Florence, and guns may have been used in France that year. In 1327, Edward III probably brought small cannon (”crakys”) north to use against the Scots, a prelude to his use of artillery against the French during the opening fights of the Hundred Years’ War (1337-1453). While such primitive weapons were useful in sieges, it may be doubted they did more than frighten inexperienced enemy troops in open battle.
The early inefficacy, general expense, and the huge difficulty of transporting cannon across difficult terrain largely untamed by law or many roads slowed the spread of gunpowder artillery. By the 1460s cast bronze, muzzle-loading cannon replaced built-up bombards, especially in France, though the older guns remained valued and in use. Despite the greater cost of bronze (three to four times that of comparable iron casting), it was preferred since it was less brittle than iron, did not rust, and was cast with fewer of the deadly imperfections that led some iron cannon to burst when fired. Two-wheeled, towed carriages also replaced older four-wheeled, unsprung gun carts.