Like the European anthem, the blue flag with 12 yellow stars, symbolising beauty and harmony, was originally used by the Council of Europe.
The flag is one of the many EU symbols that replicate the symbolism of a nation state in order to foster a common European identity and sense of community. This is in accordance with the plan of the Adonnino-Committee on a People's Europe.
Future
The EU Constitution will make the flag the official flag of the Union
Links
http://www.europa.eu.int/abc/symbols/emblem/index_en.htm