Central bank money is the foundation of modern monetary and payment systems. Central bank money defines a unit of account; the price at which this money trades determines “monetary policy”; and most payment systems require the transfer of central bank funds before a transaction is legally final, or “settled.” Despite its current ubiquity, the origins of central bank money have remained obscure, and the present-day system involves a remarkable conceptual leap from earlier coin-based systems. In this paper we recount how the critical innovation—the creation of a unit of account that could be maintained solely through open market operations—took place in the seventeenth-century Dutch Republic (for a more detailed examination see Stephen Quinn and William Roberds 2005, Quinn and Roberds 2006). The villain in our story is the incremental debasement that unsettled the quality of new coins and price of old coins. The protagonists are the Dutch authorities who contended with debasement by regulating the price of coins and by creating “exchange banks, ” the Bank of Amsterdam in particular, to assure the quality of coins. The plot is propelled forward because well-intentioned regulatory changes exacerbated the debasement