Guiomar (Wiomarch) de Léon, Comte de Léon

Léon in Brittany must not be confused with the Spanish Province of Léon.

The Viscounty (or County) of Léon was a feudal state in extreme western Brittany in the High Middle Ages. Though nominally a vassal of the sovereign Duke of Brittany, Léon was functionally independent of any external controls until the viscounts came under attack by Henry II of England. It thus became the focus of revolts and wars when Brittany was drawn into the Angevin empire.

The history of Léon's early counts is obscure. The original vicecomites (viscounts) of Léon were public officials appointed by the comites (counts) of Cornouaille, but by the mid-eleventh century they had usurped public authority in their province. Their ability to remain independent of both count and duke was likely due to their remoteness in the extremity of the Armorican peninsula. Unlike their Breton neighbours they did not participate in the Norman conquest of England in 1066.[1] Count Harvey, however, did participate on the side of Stephen of Blois in the nineteen years of civil war in England called The Anarchy.