Iceland is a member of the Schengen Area. The practicalities of free movement within an area without internal border controls were first set out by the Schengen Agreement in 1985 and the subsequent Schengen Convention in 1995 that abolished controls on internal borders between the signatory countries. The Amsterdam Treaty on the European Union, which came into force on the 1 May 1999, incorporated the set of measures adopted under the Schengen umbrella into the Union’s legal and institutional framework. The Schengen area encompasses 22 EU member states as well as Iceland, Norway, Liechtenstein and Switzerland. New applicants to the Union will have to fulfill these same requirements. The Schengen principles of free circulation of people are backed by improved and still developing security measures to ensure that the EU's internal security is safeguarded.