The concept of a monetary union today implies a multilateral entity that centralizes the emission of a common currency shared by multiple countries. This arrangement provides benefits, such as lower transaction costs, but poses challenges, especially without a complete fiscal union, which can create perverse incentives. However, monetary issues are not new; they have been a consistent aspect of human organizations throughout history. Today, we will discuss how the politically fragmented German lands under the Holy Roman Empire established a common currency in the sixteenth century and examine the debates surrounding its perceived success or failure.