Turkey has enjoyed challenging and intricate relations with the European Union (EU) for over half a century. Official ties began in 1963 when Turkey and the then-European Economic Community concluded an Association Agreement that ushered in freer trade and closer political cooperation. Bilateral ties leapt forward with the establishment of a customs union in 1996. Nineteen years later, the EU launched accession negotiations with Turkey in
Source: http://www2.lse.ac.uk/IDEAS/publications/reports/SR007.aspx