The Benelux countries (Belgium, Luxembourg and the Netherlands) had already set up a common passport area in 1970. In 1984, following protests by truck drivers over delays at border crossings between France and Germany, the two countries signed a bilateral agreement to remove controls along their shared border. This means that Schengen Member States that were not part of the EU have few formally binding options to influence the development and development of Schengen rules; their options are effectively reduced to approval or exit from the agreement. However, consultations are being held with the countries concerned prior to the adoption of certain new provisions.  While the original intention to remove border controls was to facilitate the free movement of citizens of participating countries, it was not possible to remove border controls for these travellers while maintaining screenings for travellers from third countries. This is why the concept of free movement of persons has been broadened to allow external visitors to move freely within the Schengen area. The abolition of border controls for these external visitors required careful coordination on who was allowed to cross external borders to move freely within the Schengen area. Denmark also has a unique position with regard to Schengen, because, unlike other Schengen countries, it can decide whether or not to take new decisions under the Schengen agreements. In another case, the visa application resulting from the Schengen agreements corresponds to any visa procedure. You apply, send your passport and then receive a stamp if you are approved. However, they must meet certain criteria and requirements in order to qualify for a visa under the Schengen Agreement. One of the most remarkable requirements is Schengen visa insurance.
With the entry into force on 1 May 1999 of the Schengen Protocol of the Treaty of Amsterdam of 2 October 1997, Schengen cooperation was transposed into EU law, initially solely on the basis of an international agreement. People and goods can move relatively freely along the internal borders of the 26-state Schengen area. The idea is that the agreement, to which 22 EU countries belong, as well as Iceland, Liechtenstein, Norway and Switzerland, will stimulate the domestic economy and facilitate human mobility in a way that only a few regions of the world allow. In addition to increased information exchange, Schengen has also strengthened police coordination in the observation and prosecution of alleged perpetrators.