Ah yes, the sparth.

So, quite simply, Ireland is a weird place. When we’re talking about the development of arms and armor, it’s oddly distinct from the rest of Europe, especially for the fact that they never seem to adopt plate armor in any real capacity.

Light armor is the name of the game, even into the 16th century, and the Gallowglass, considered a mercenary elite, were some of the most heavily armored blokes on the field, typically only wearing a maille hauberk and a helmet of some kind (with padding beneath.)

(Hands together for Osprey illustrations.)

The sparth is suggested to be a descendant of the (in)famous Dane axe of Viking era fame. As armor in Europe develops, so too do the weapons trying to defeat that armor, so axes like the poleaxe, which is far more equipped for dealing with plate, become popular.

However, since here in Ireland you don’t have heavier armor really developing (it’s been suggested because of the nature of the Irish countryside and Irish warfare at the time) then a large, two handed axe like the sparth fills its purpose perfectly. It wreaks havoc on opponents only armored in cloth, and certainly transmits enough force to give an opponent in maille a bad time.

So we’ve established that the sparth is an effective weapon an Irish military context. The reason they are so synonymous with the gallowglass is because the weapon is so well suited to their role on the battlefield as heavy infantry. The gallowglass were a sort of flank guard, and often served to cover the escape of the other troops with the cattle they were stealing (which was the vast majority of Irish warfare.)