EUROPEAN UNION, TREATY ON

also called Maastricht Treaty, international agreement approved by the heads of government of the states of the European Community (EC) in Maastricht, Neth., in December 1991. It was ratified by all EC member states before Nov. 1, 1993, when it came into force. The treaty established a European Union (q.v.; EU), with Union citizenship for every person holding the nationality of a member state. It also provided for the introduction of a central banking system and a common currency (European currency unit; see ecu), and it committed the EC nations to implementing a common foreign and security policy.