In the historical review you will read that the Council of Europe adopted the circle of 12 stars in 1955. The Council of Europe agreed to the use by the European Community (since the Maastricht Treaty the European Union) of the European flag that it had adopted in 1955 and Community institutions have been using it since the beginning of 1986.
<!--EZCODE BOLD START--> The symbolic description they gave to the emblem is: the symbol of perfection and entirety.<!--EZCODE BOLD END-->
You will receive a copy of the graphic manual in a few days.
Sincerely yours,
Paul Leunen
Seems like they just decided that the 12 stars would symbolise perfection and unity. There is no historical basis other than that. They can do that you know, these bureaucrats. :lol