Since the foundation of the Republic, Turkey has been part of international organisations in the European continent in the aftermath of the end of the Second World War. Turkey joined the Council of Europe in 1949, the North Atlantic Treaty Organisation (NATO) in 1952; and after the foundation of the European Economic Community (EEC) in 1958, it formally launched an association application to the Community on the 31st July 1959.
Upon receiving the application, the EEC Council of Ministers confirmed Turkey’s application, and proposed to sign an Association Agreement that would be effective until membership requirements would been met. With the signature of the Ankara Agreement on the 12th September 1963 and its entry into force on the 1st December 1964, Turkey-EU Association relations formally started (1963-1999 Period). In this period, important developments have taken place in Turkey-EU relations but perhaps the single most significant turning point was the confirmation at the Helsinki Summit in 1999 of Turkey’s candidate status (1999-2005 Period). Subsequently, at the 17th December 2004 Brussels Summit, EU Heads of State and Government confirmed that Turkey had met sufficiently the political criteria and thus took the decision to start accession negotiations with Turkey on the 3rd October 2005, opening a new period in Turkey-EU relations.
Source: Ministry of EU Affairs: http://www.ab.gov.tr/index.php?p=4&l=2