Denier - Odo I

Odo I's tenure as Duke of Brittany was contested almost from the start — his father Alan III died in 1040 leaving a duchy fractured by rival Breton lords and persistent Norman pressure from the east. The coinage issued under his name reflects administrative ambition more than political stability; Odo died in 1047, still a minor, having never fully consolidated ducal authority.

Billon deniers of this period survive in small numbers, most heavily worn from the active commerce of western Breton markets.