1 Ducat - Frederick William Guinea-Ducat

Frederick William — the "Great Elector" — struck these ducats during the final years of his reign, a period defined by his aggressive consolidation of Brandenburg-Prussia into a coherent military state. The Guinea-Ducat designation reflects a deliberate monetary policy: these were struck to the weight and fineness standard of the English guinea to facilitate trade with English and Dutch merchants in the Baltic, where Brandenburg's newly established naval ambitions depended on foreign commercial relationships.

Frederick William died in 1688, cutting this issue short at three years.