1 Pfennig - Frederick William IV

Prussia's pfennig coinage of this period was administratively tied to the Customs Union — the Zollverein — which pushed member states toward weight and denomination standardization through the Dresden Coinage Convention of 1838. Frederick William IV, who came to the throne in 1840, inherited that framework and never quite escaped it, despite his well-documented resistance to the liberal constitutional pressures that would define his reign and ultimately break his health before his death in 1861.

The KM#451a variant reflects a documented composition adjustment mid-series — worth distinguishing from the base type when attributing examples from the later years of the run.