I wouldn't consider the conflicts in Brittany and the Aquitaine (among other places) during the Hundred Years War just your typical local feudal conflicts, as apart from these being very large and powerful territories in their own rights, the fighting was contextually a part of the larger conflict between the King of England and the King of France, with the opposing forces aligned with one or the other larger ruler (not just independent) and the kings taking an active, if sometimes secretive, interest in their affairs, often offering significant support with the hope of improving their own positions either militarily or diplomatically.

It was not a hundred years of 'hot' war directly between the two main forces involved, but conflict that WAS a part of the overall war continued pretty much throughout. There were of course also semi-independent brigands fighting throughout who might or might not declare allegiance to one side or the other, or who might change sides, and conduct war simply for personal economic benefit, but these were in addition to, not in place of, the major aligned partisans fighting each other.

Ajax