24 Mariengroschen Jérôme Bonaparte

Jérôme Bonaparte's Kingdom of Westphalia was a Napoleonic construction assembled in 1807 from Prussian, Hessian, and Brunswick territories — handed to Napoleon's youngest brother as a model constitutional monarchy meant to demonstrate that French-style governance could function on German soil. The 24 Mariengroschen denomination was a deliberate retention of the old north German accounting unit, a concession to local commercial habit in a kingdom otherwise aggressively remodeled along French lines.

Westphalia's coinage came to an abrupt halt in 1813 when coalition forces swept through and Jérôme fled, making the entire run a tight six-year window.