The Third pillar of the European Union – the cooperation in the fields of justice and home affairs - was established by the Treaty on the European Union. The very Treaty on the European Union, known as the Maastricht Treaty, effective since 1 November 1993 represents an undisputed success of the European efforts to continue and develop the integration, including the establishment of the area of freedom, safety and cooperation in the framework of the Community.

Following the Amsterdam Treaty, a large part of the content of the Third pillar, concerning the free movement of persons (visas, asylum, immigration policy) has become the acquis communautaire by its assuming into the newly established Chapter IV. of the Treaty establishing European Community. The Schengen Agreements, which until then stood apart from the acquis communautaire as well as the Treaty on European Union, were also overtaken to the system of the Third pillar. The Third pillar was thus definitely re-constructed – fields were modified, new legal instruments were introduced, the role of Community bodies was specified and the cooperation among states was strengthened. With regard to the Chapter VI. of Treaty on European Union, i.e. the field still covered by the third pillar (police and judicial cooperation in criminal matters) it is stipulated that the European Union shall ensure to its citizens a high level of security within the area of freedom, safety and justice in particular by strengthening of the cooperation among the Member States in the fields of police and judicial cooperation in criminal matters and the fight against racism and xenophobia.

The cooperation in field of justice and home affairs thus laid foundations of the collaboration between Ministries of Justice and Ministries of Interior and their respective units of all fifteen Member States of the European Union. This collaboration enables a dialogue, mutual assistance, joint efforts and cooperation among police forces, customs administration, migration offices and judiciary in the Member States.