What is the proper length for a longsword or two handed sword when recreating medieval combat technique? The answer depends on the size of the user’s body, since the sword should ideally be proportioned to the user. It also depends on the period and fighting school one is trying to replicate. Vadi, writing ca. 1482-1487, says that “the sword should be of the correct measure, with the pommel just under the arm”. That is, the length of the sword should reach from the ground to just below the armpit. Further, the handle and cross of the hilt should both be a span long, that is, the distance between the thumb and tip of the little finger with the fingers spread. This measure of the handle does not include the length of the pommel.
Iconography and surviving weapons suggest that a shorter length was more typical ca. 1380-1400. Swords with two handed grips shown on effigies from that period might have a length that reached from the ground to perhaps a handbreadth (or four inches). higher than the owner’s navel, and a grip perhaps an inch or so less than a span. This is the era when Liechtenauer was writing. The longswords in Talhoffer seem to be intermediate between this length and what Vadi recommends.
Later masters such as Marozzo, di Grassi and Meyer seem to prefer a weapon that is longer than Vadi’s ideal length, both overall and in the grip. George Silver, on the other hand, recommends that a two handed sword have a blade that is shorter than Vadi’s ideal length, and more like those of 1400 or so.