Schengen represents an area of free movement where the border checks at the internal borders of the signatory states have been abolished and a single external border where the checks follow a strict set of rules was created

1. The chronology of Schengen accession is as follows:
   
   1985- Belgium, Netherlands, Luxembourg, Germany si France
   1990- Italy
   1991- Spain si Portugal
   1992- Greece
   1995- Austria
   1996- Denmark, Sweden si Finland
   2001- Island si Norway
   
   The participation of Island and Norway
   Together with Sweden, Finland and Denmark, Norway and Island are part of the of the Nordic Union of Passports, in which the checks at the internal borders were eliminated. Island si Norway signed an agreement with EU in May 1999, on the basis on which the two states can participate to the elaboration of the new instruments of the Schengen acquis. The acts are adopted only by EU member states, but there are also applicable to Island and Norway. In practice, this association takes the form of a mix committee outside the EU framework, formed by representatives of Island, Norway, UE Council and European Commission.
   
   
2. The decision regarding the extension of Schengen area was taken at the end of 2007 by the UE Council, thus, in 21 of December 2007 the checks at the land and sea borders were eliminated in the 9 member states (except Cyprus) who acceded in 2004 and at the end of march 2008 the checks for Schengen internal flights were eliminated.

Czech Republic Estonia Latvia

Lithuania Malta Poland

Slovakia Slovenia Hungary

	The freedom of movement is granted in the territories of 26 Schengen member states, without checks at internal borders – from Portugal to Poland  and from Greece to Finland.

3. The decision regarding the enlargement of the Schengen area was taken in December 2008 by the EU Council; thus, on 12.12. 2008,  controls at land borders were eliminated for Switzerland. Controls at air borders were eliminated starting with the end of March 2009.
   
   
4. The decision regarding the enlargement of the Schengen area was taken in Decemeber2011 by the EU Council: thus, on 19.12.2011, controls of the internal borders were eliminated for Liechtenstein.
   
   
5. States acceding to Schengen.
   
   • Cyprus decided to postpone the implementing of the Schengen Acquis on SIS(Schengen Information System), but intends to connect to SIS II, once it becomes operational.
   • Romania and Bulgaria.  The Schengen acquis was accepted in full starting with the preparation for joining the  EU. Both states presented the Declaration of Readiness for the Schengen evaluation. 2011 represents the timeframe for the accession of the two EU member states to Schengen.
   Romania fulfilled all the assumed Schengen obligations. Thus, all the Schengen evaluation reports of Romania were adopted within the successive Scheval WG, in Brussels. Bulgaria was re-evaluated at the end of March 2011 in the field of land borders. The act which marks the accession of Romania and Bulgaria to the Schengen area is the Council Decision for the full application of the Schengen acquis in Romania and Bulgaria.
   • Croatia notified its Declaration of Readiness for starting the Schengen evaluation in 2015.