The 12 stars in a circle symbolise the ideals of unity, solidarity and harmony among the peoples of Europe.
The melody used to symbolise the EU comes from the Ninth Symphony composed in 1823 by Ludwig Van Beethoven.
The ideas behind the European Union were first put forward on 9 May 1950 by French foreign minister Robert Schuman. This is why 9 May is celebrated as a key date for the EU.
"United in diversity" is the motto of the European Union.
It signifies how Europeans have come together, in the form of the EU, to work for peace and prosperity, while at the same time being enriched by the continent's many different cultures, traditions and languages.