Few terms in law and philosophy have had as long a life and as important a role in modern history as the idea of equality (SA Lakoff, Harvard University Press, 1964). This is visible in the history of equality in the European Union, which has striven to keep up with the diversity of its peoples, despite a slow start. Since the founding Treaties were signed in the 1950s, European equality law has become far more complex. Theories, themes and definitions of equality and discrimination have developed over time and have been greatly influenced by cases brought by ordinary people. Equality and anti-discrimination are areas of European law that directly serve the individual. They are therefore of interest to us all. Combating discrimination and promoting and achieving equality have become prominent, important and challenging issues in European life.

European enlargement into a Union of twenty-five diverse Member States in 2004, was a historic turning point of political, legal and social significance and a ‘reunification’ of such magnitude that perhaps it cannot be appreciated fully, except in retrospect. It contrasts dramatically with the original European (Economic) Community of six geographically close Member States. This most ambitious enlargement, which incorporated new regions, new peoples, new languages, new opportunities and new fears within the Union, has also influenced the recent dynamism in European equality law and simultaneously presents a variety of challenges for the European equality matrix.