The euro is for many reasons a remarkable legal tender. Even though formally introduced only in 1999, it soon became the second most important currency after the US Dollar in the international monetary system. The 20th anniversary of the euro offers an ideal occasion to reflect on decisive factors underlying its successes and failures. Employing a combined approach that links aspired reforms of the Economic and Monetary Union with novel topics arising from financial technology, this article derives important lessons for the next generation of virtual currencies and furthermore proposes a set of guiding principles for modern regulation and supervision. As a result, the study contributes to safeguarding the financial order in a global and dynamic environment.