1 May 2004: the EU’s eastern enlargement

30.04.2014 - Article

The Treaty of Accession allowed 10 eastern and southern European countries to become members of the EU on 1 May 2004. In many places this was marked by public celebrations.

Public celebration in Słubice in the night from 30 April to 1 May 2004
Public celebration in Słubice in the night from 30 April to 1 May 2004© dpa/Picture Alliance

The Treaty of Accession regulated the EU’s enlargement to allow 10 eastern and southern European countries to become members of the European Union on 1 May 2004. This largest round of enlargement in the EU’s history was marked by public celebrations at many border crossings and in the European capitals.

As midnight struck to herald 1 May 2014, Europe’s anthem “Ode to Joy” rang out from huge loudspeakers in Frankfurt and Słubice, two towns on opposite sides of the river Oder, and fireworks exploded in the night sky. Then Germany’s Foreign Minister at the time, Joschka Fischer, and his Polish colleague Włodzimierz Cimoszewicz symbolically opened the border point at the Oder Bridge which links the two towns. Hundreds of visitors crossed the bridge that night, in both directions, to celebrate on both banks of the Oder. It may not have occurred to them as they partied that they were also exercising one of the European Union’s fundamental freedoms, free movement of persons.

Largest round of enlargement in the EU’s history

Similar celebrations took place in many places across Europe that night, but particularly in the capitals of the new acceding states and at major border crossings. As well as Poland, the other countries joining the European Union on 1 May 2004 were Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Slovakia and Slovenia, making this EU enlargement the largest round of enlargement to date.

Gerhard Schröder and Joschka Fischer signed the Treaty for Germany
Gerhard Schröder and Joschka Fischer signed the Treaty for Germany© AA

The “eastern enlargement project” had begun a long time before: in the early 1990s, after the end of the Cold War, the EU concluded Association Agreements with many central and eastern European states with the aim of liberalising trade, developing guidelines for political dialogue and harmonising national laws and regulations with EU law. The moves towards accession were supported by a broad-based EU financing programme. The negotiations on accession which were launched with 10 states in 1997 were completed in 2002. The Treaty of Accession was finally signed in Athens on 16 April 2003.

Referendums on accession

The actual Treaty is very brief and to the point: it consists of just three articles, the rest of the details are regulated in various annexes. There then follow seven pages with the signatures of all 15 EU member states plus the 10 candidate states.

Once it had been signed, the Treaty had to be ratified in all member states and candidate countries. Referendums were held in most of the candidate states; in some cases (e.g. Slovenia and Slovakia) over 90 percent of the population voted in favour of EU accession.

Peace and stability in Europe

Ten years on from this enlargement round, it is difficult to imagine a European Union without Poland, Hungary, Cyprus or the Baltic states. The accession of these 10 countries to the EU not only increased free movement of persons and freedom of travel: above all it made an important contribution to peace and stability in Europe.

Further information

Treaty on Accession, 16 April 2003 (in German) PDF / 158 KB

Enlargement of the European Union: milestones and future outlook

Parameters of the enlargement process

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