The Treaty on European Union (TEU), signed in 1992 in Maastricht, established the foundation for the modern European Union. It introduced key concepts such as European citizenship and laid the groundwork for the creation of the Euro, the common currency used by many EU member states. The treaty aimed to enhance political and economic integration among European countries. The TEU also set out the principles of cooperation in areas like foreign policy and security. It established the framework for the EU's institutional structure, including the roles of the European Parliament, European Commission, and European Council, promoting democratic governance and decision-making within the Union.