Louis I ruled Savoy from 1440 until his death in 1465, a reign defined by the slow erosion of ducal authority as Savoy became increasingly entangled in the competing ambitions of France and the Italian states. The patac was a low-value billon piece circulating in that fractious environment — the word itself derives from the regional term for a small struck coin, and versions of it circulated across multiple Savoyard issues making die attribution genuinely difficult. Biaggi's numbering separates them where MIR treats overlapping types more broadly, which accounts for the dual reference here.
Louis I ruled Savoy from 1440 until his death in 1465, a reign defined by the slow erosion of ducal authority as Savoy became increasingly entangled in the competing ambitions of France and the Italian states. The patac was a low-value billon piece circulating in that fractious environment — the word itself derives from the regional term for a small struck coin, and versions of it circulated across multiple Savoyard issues making die attribution genuinely difficult. Biaggi's numbering separates them where MIR treats overlapping types more broadly, which accounts for the dual reference here.