1 Thaler - Frederick William

Nassau was reorganized as a unified duchy only in 1806, when Napoleon consolidated the patchwork of Nassau territories under Friedrich Wilhelm as part of the Confederation of the Rhine. This coin dates to just the third year of that arrangement. The duchy's coinage before unification had been a jurisdictional nightmare — multiple lines issuing separately — and the 1809 Thaler was among the earliest attempts to project a single, coherent monetary identity across the newly merged lands.

Friedrich Wilhelm died in 1816 without male heirs, ending his line and transferring Nassau to a collateral branch.