Treaty on European Union

Upon its signing in 1992, the Treaty on European Union, also known as the Maastricht Treaty, provided the framework for the multinational polity called the European Union (EU). The treaty was a pivotal effort by the European nations to unify politically so as to increase the region's economic integration and establish joint policies on the environment, defense, citizenship, justice, health care, transportation, and the like. The Treaty on European Union called for the creation of a single currency, originally the European Currency Unit, which was later reborn as the euro, and for the establishment of a central bank that would coordinate monetary policies among the member nations. By eliminating tariffs on goods imported from one EU country to another and by relaxing border and immigration policies, the treaty—in line with its predecessor treaties—made Europeans freer to work, live, study, travel, and purchase goods and services in any of the EU's member states.

In late 1991 the heads of government of the EU's twelve original member states approved the treaty, which was then signed in early 1992 in the Dutch city of Maastricht. The twelve founding nations were Belgium, Denmark, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Spain, and the United Kingdom. The treaty required the approval of voters in each of the member states, and while there was widespread support for the treaty's goals, many European voters were reluctant to give up control of their economies. Voters in Denmark initially opposed the treaty by a narrow margin, but in a later vote, in May 1993, they reversed course and approved it. Britain, too, proved resistant to some of the Treaty on European Union's provisions, and that nation, along with Sweden, did not immediately support a common currency. Britain did join the currency union in

After the ratification process was complete, the EU, with headquarters in Brussels, Belgium, was established in late 1993. From its original membership of twelve nations, the EU expanded to twenty-eight nations over the ensuing years. Austria, Finland, and Sweden joined in 1995. In 2001 the Treaty of Nice (France), addressed issues related to the expansion of the union. Accordingly, ten more countries—Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia—joined in 2004, and Romania and Bulgaria joined in 2007. Croatia joined in 2013. However, in a massive reversal, the United Kingdom withdrew from the EU in 2020, making it the only sovereign country to have left the EU.