Le Hir was born in Plougastel, Finistère.
He participated in Skol Ober, correcting students' homework.
He was county chair for the Parti National Breton in Landerneau.
During World War II, Le Hir was a member of the militia working with the Germans against the French Resistance.
He was a member of the Kommando de Landerneau, "German group charged with the repression of all attempting to go against the surety of the army."