European Union (EU).
Collective term for the 26 European countries - 22 EU member states, plus four other countries - which have open borders between them.
The 22 participating EU member states are:
- Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain and Sweden.
The other four members of the Schengen Area are:
- Iceland, Liechtenstein, Norway and Switzerland.
Four EU member states expected to join Schengen
The following EU member states are expected to join the Schengen Area in due course:
- Bulgaria, Croatia, Cyprus and Romania.
Two EU member states opted out of Schengen
Ireland and the United Kingdom (UK) opted out of the Schengen arrangements.
The UK subsequently left the European Union itself.
The originating Schengen Agreement was signed in 1985 in the Luxembourg village of Schengen, by five countries:
- Belgium, France, Germany, Luxembourg and the Netherlands.