Maastricht Treaty

A treaty ratified by all European Union member states in 1993 and implemented by means of extensive amendment to the Treaty of Rome, including the change from the name European Economic Community to European Union. The Treaty includes sections on political union and on economic and monetary union, as well as a redefinition of the role of legislative and executive bodies. It establishes the principle of subsidiarity, by which any action by the Union shall not go beyond what is necessary to achieve the objectives of the treaty.