Denier - Louis I Altenheim mint

Louis I — "the Pious" — inherited Charlemagne's unified empire in 814 and spent the following decade trying to hold it together through a combination of ecclesiastical reform and increasingly resented central authority. The Altenheim mint, active in the Alsace region, was one of several royal mints brought under tighter crown control during Louis's early reign as part of a broader effort to standardize coinage across the Frankish territories — a project his father had begun but never fully completed.

The gap in Prou's Carolingian catalog for this type is worth noting: its absence there, against citations in Gariel and Morrison, suggests a piece that circulated within a narrowly documented regional network.