EU Citizenship originates in the free movement of workers in the Common Market. This evolved into the Single Market (1993) with its free movement of people.
European Economic Area
The area that provides the free movement of people, services and capital within the European single market.
Membership is open to member states of either the EU or the European Free Trade Association (EFTA).
EFTA states which are party to the European Economic Area Agreement participate in the EU's internal market without being members of the EU.
However, they must adopt most EU legislation concerning the single market except on laws concerning agriculture and fisheries.
Article 20 of the Lisbon Treaty
— to strengthen the protection of the rights and interests of the nationals of its Member States through the introduction of a citizenship of the Union ;
CITIZENSHIP OF THE UNION Article 8 1 . Citizenship of the Union is hereby established. Every person holding the nationality of a Member State shall be a citizen of the Union. 2. Citizens of the Union shall enjoy the rights conferred by this Treaty and shall be subject to the duties imposed thereby.