It takes its name from the city of Schengen in Luxembourg, where the agreement was signed in 1985. It entered into force in 1995. Germany, France, Spain, Portugal and Benelux were the first to implement the agreement in 1995. Two years later, Austria and Italy were added, Greece in 2000 and Iceland, Finland and the Scandinavian countries in 2001. Originally, the Schengen Treaties and subsequent rules were officially independent of the EEC and its successor, the European Union (EU). In 1999, they were transposed into European Union legislation by the Treaty of Amsterdam, which provides for Schengen, codified in EU law, while providing for opt-outs for Ireland and the United Kingdom, the latter providing for opt-outs since leaving the EU. EU Member States that do not have an opt-out and have not yet joined the Schengen area are legally obliged to do so if they meet the technical requirements. Although it is linked to EU law, several non-EU countries that have signed the agreement are included in the territory. Although Switzerland is not a member of the EU, it has strong economic and social relations with many Schengen states due to its position at the heart of Europe and is part of the European Free Trade Association (EFTA) with Iceland, Norway and Liechtenstein (other non-Schengen countries). Switzerland became an integral part of the Schengen area after signing the agreement on 26 October 2004 and starting its implementation on 12 December 2008. In December 1996, two non-EU states, Norway and Iceland, signed an association agreement with the signatories to the agreement to become part of the Schengen area. Although this agreement never entered into force, both countries became part of the Schengen area after similar agreements were concluded with the EU.
 The Schengen Convention itself has not been signed by non-EU states.  In 2009, Switzerland concluded its official accession to the Schengen area with the adoption of an Association Agreement by referendum in 2005.  Differences of opinion between Member States led to an impasse over the abolition of border controls within the Community, but in 1985 five of the ten Member States at the time – Belgium, France, Luxembourg, the Netherlands and West Germany – signed an agreement on the phasing out of common border controls. . . .