The article discusses the history of European efforts to create a single currency, starting from the Treaty of Rome in 1957 to the establishment of the euro in 1999. It highlights the steps taken towards economic and political integration, leading to the concept of economic and monetary union (EMU) as a way to achieve political unity. The experience with the exchange-rate system called the snake is also examined. Overall, the article shows how Europe moved towards a United States of Europe through monetary integration.