1 Öre - Johan, Duke of Östergötland

Johan of Östergötland was the son of Karl IX and younger brother of Gustav II Adolf, granted the duchy as an appanage under the terms of the Swedish dukedom system that Karl IX had formalized — and that Gustav II Adolf would later move to dismantle, wary of the centrifugal pull of semi-autonomous princely territories. These small billon issues circulated within the duchy's borders during a period when Sweden was simultaneously fighting Denmark, Russia, and Poland, and copper was being aggressively diverted toward military use.

The KM numbering reflects at least three distinct die varieties across the emission period.