11 May - The electorate of Lithuania votes to join the European Union, becoming the first former Soviet republic to do so.
Soviet Union | European Union | Union Army | 2003 | rugby union | European Parliament | Union | Member of the European Parliament | European Commission | 2003 in music | International Telecommunication Union | trade union | European Space Agency | Union (American Civil War) | Union Pacific Railroad | England national rugby union team | European | 2003 invasion of Iraq | European Court of Human Rights | American Civil Liberties Union | Wales national rugby union team | New Zealand national rugby union team | Ireland national rugby union team | European Court of Justice | Western Union | Scotland national rugby union team | International Astronomical Union | Georgia national rugby union team | Trade union | International Union for Conservation of Nature |