From the web site of "The Medieval Combat Society" we have the historical timeline, gunpowder and cannon. Gunpowder and cannon used at an earlier date with much greater regularity that I had suspected, at least by the time of the last Crusades quite widespread on an international scale.
And in all variations too. Flame lances, hand grenades, firearms [guns] and cannon. Arsenals and depots apparently detonating in China quite frequently, on an almost clockwork basis, the destruction I would have to assume very widespread and frightening.
This Chinese depiction shows troops ["foreign devils" almost literally so] using flame lances and hand grenades. The suggestion is that such weaponry is the work of mysterious and diabolical forces?
And yes, during the siege of Calais the English did have cannon at their disposal.
This is the type of cannon as the English would have used at Calais. Firing too a stone projectile.
"Early Medieval Cannon"
"It is thought that gunpowder was invented in China and found its way to Europe in the 13th Century. In the mid to late 13th Century gunpowder began to be used in cannons and handguns, and by the mid 14th Century they were in common use."
St. Barbara the patron of gunners.