The Treaty on European Union, commonly known as the Maastricht Treaty, is the foundation treaty of the European Union (EU). Concluded in 1992 between the then-twelve member states of the European Communities, it announced "a new stage in the process of European integration" chiefly in provisions for a shared European citizenship, for the eventual introduction of a single …

A referendum on the Maastricht Treaty was held in Denmark on 2 June 1992. It was rejected by 50.7% of voters with a turnout of 83.1%. The rejection was a blow to the process of European integration, although the process continued.The result of the referendum, along with the "petit oui" in the French Maastricht referendum signaled the end of the "permissive consensus" on …

Maastrichtin sopimus allekirjoitettiin 7. helmikuuta 1992 Maastrichtissa, Alankomaissa, Euroopan yhteisön jäsenien kesken. Sopimus astui voimaan 1. marraskuuta 1993. Se syntyi talous- ja rahaliittoa ja poliittista yhteistyötä koskevien erillisten neuvottelujen tuloksena.