These rules -- known as the Schengen "acquis" -- established a common visa system and led to the Schengen Information System (SIS), a computer system for police and customs officers to access data about people.
In 1997, controls are abolished with Austria and Italy, with Greece
following suit in 2000.

In 2001, Denmark, Finland and Sweden join, but also two nations that are
not members of the European Union -- Iceland and Norway. The five had already established their own Nordic Union on passports in 1954.

On December 21, land and maritime borders will disappear with nine of the
10 mainly ex-communist states which joined the EU in 2004 -- Cyprus hopes to join the others in 2008.

Then on March 30, 2008, airport controls will also be lifted with the nine:
the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia.

This will bring to 24 the number of nations fully integrated into Schengen.
Outside the zone, Switzerland -- which is surrounded by EU countries but is not a member -- voted in a referendum in 2005 to join Schengen and hopes to join in November 2008, along with tiny Liechtenstein.

For Bulgaria and Romania, which joined the EU on January 1, evaluation
missions have begun but they will not be able to take part for at least two
years.

Britain and Ireland, meanwhile, apply certain parts of the pact on police
cooperation. They plan to contribute to and use an updated version of SIS --
SIS II -- which could begin operation late next year. For the moment, they do
not intend to sign up to Schengen and retain their own visa policies.
AFP