On February 7, 1992 the Maastricht Treaty was signed in Maastricht, Netherlands creating the European Union. The 12 original signatories were Belgium, Denmark, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, and the United Kingdom.
Finland and Sweden joined in 1995 and Austria in 1999.
In 2004, the EU saw its biggest enlargement when Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia and Slovenia joined.
Bulgaria and Romania joined in 2007, followed by Croatia in 2013.
Conspicuously absent is Norway, which has twice rejected membership in public referendums.
On January 30, 2020 the United Kingdom became the first coutry to leave the European Union.

The European Union flag was designed by Arsène Heitz and the 12 stars stand for the 12 original signatories. Hmmmm. . .will it have to be redesigned?