Monetary crises as well as disruptions of the financial system have been part of European history since the late Middle Ages. The essay argues that these developments reveal remarkable limitations to legal power and financial sovereignty: From the very beginning, the power to set monetary value was in the hands of the rulers, kings and queens, princes and even city councils. There were, however, legal limits to their discretion. These limits developed from the idea that the users of mints and money should not be at the mercy of their rulers when it came to monetary value, particularly concerning debasement and devaluation. While such legal rules did not always prove effective, fiscally driven devaluations were frequently without lasting imp...