Weaponry
During this time period, the sword, naturally, remained the primary weapon of the armoured knight. However, different varieties of the archetypal weapon were beginning to emerge at this point.
Due to the changes in armour, and the fact that it was getting heavier, and therefore harder to get through, the sword was being changed toward use as either a thrusting weapon, or the alternative, a heavier cutting blow than had ever been used before.
To facilitate the physics needed for a sword capable of easily taking a man's arm off, the blade was made longer as well as the grip. This meant that the sword could be used easily with two hands, thus providing the leverage necessary for such devastating blows.
These heavy swords were closest to what swords had originally been, but they weren't the only change. Another kind of weapon became popular: smaller, lighter, double-edged swords with a severe taper down to the point. This was a sword designed to thrust. The small tip of the weapon was designed specifically to get wedged between the plates of armour.
Another feature of the design of thrusting swords was the advent of a blunted length of blade just above the cross guard - the ricasso. This was made so that the wielder could safely rest the index finger on the blade, giving massively more control over the point. The pommel as well was specialized - wider than would be on a normal sword, so that a hand could be placed there to shove the weapon in even harder.
Daggers were also carried alongside the sword, presumably as a sort of backup weapon, or for use in closer combat. The three basic sorts of daggers were quillion daggers, which looked like tiny swords, ballock daggers, which were of simpler construction with grips and cross guards made of horn or bone rather than steel, and the final form, the rondel dagger. The rondel dagger was designed with a round disk instead of a cross guard, and another in place of the pommel. This way, it provided a modicum of defense for the hand, and also made it much less likely to slip out of a person's grasp.
Another effect of armour becoming heavier was the crushing weapons such as warhammers and maces becoming heavier. Maces in particular had been in use for some time prior to the 1300s, however, the earliest ones were most often made of light metals such as bronze, and were only mounted on wooden shafts. When armour became impossible to penetrate with the lighter weapons, versions made fully of steel came into wide use.
Warhammers with very sharp rear spikes were carried as supplementary weapons. As one would imagine, these were exceedingly useful for crushing helmets, and indeed many of the bodies from the Wisby graves show the unmistakable signs of such injuries.
The axe was also coming into popularity among the more noble members of society. It had previously been used extensively by the lower class soldiers, but came back into vogue as the need for heavier weapons increased. Much like the warhammers, axes were often equipped with a rear spike as well.
Obviously, there were other innovations in the form of pole arms and bows, but these were the most common weapons in wide use among all classes of soliders.