Denier - Charlemagne Lyon mint, monogram

The monogram denier type was introduced as part of Charlemagne's monetary reform of 793–794, which standardized the Frankish silver penny at a heavier weight and banned the older, lighter issues. Lyon was one of a handful of authorized mints permitted to strike under the new system, its output identifiable by the mint signature worked into the reverse field. The reform was itself partly a response to debasement under previous Carolingian rulers and partly an assertion of royal control over a currency that had fragmented badly across regional ecclesiastical and secular minting authorities.