Idea of European unity is old; its background can be found before Second World War. Serious, real, and peaceful ideas of cooperation between European countries, free from hegemonic aspirations, rose after painful and horrible wars between France and Prussia in 1870, and First World War from 1914. till 1918. Divided for centuries "Old continent" was arena of great world conflicts and wars but at the same time it was fat soil for true actions and efforts for European unity. After First World War looking up to creation and good functioning of United States of America , founder of pan European movement, Austrian Kalergi suggested in 1923. creation of United European States. Six years later in 1929. French minister of foreign affairs Aristide Briand together with German minister Gustavo Stressmannom, at the session of assembly of League of Nations in Geneva suggested founding of European Union as a closer cooperation of states without undermining of states sovereignty. Obviously it was necessary for Europe to get destroyed once more and to reach the edge of economic disaster so that ideas of unity could arise again.

In a various number of efforts for creation of United Europe it was important speech of British Prime Minister Winston Churchill from September 1946. in Zurich , in witch he calls on European continental states to found United European States. Churchill's opinion was that the basic assumption of united Europe was cooperation between France and German.

Illustration of founding and gradual development of EU by important dates:

• April 18^th 1951.
  Six European states: Western Germany , France , Italy , Belgian, Netherlands , and Luxemburg signed Treaty which established the European Coal and Steel Community (ECSC) in Paris . France Minister of foreign affairs Robert Schumann and well known France economist Jean Monet in 1950. put out so called Schumann's declaration which assumes establishing of ECSC, actually putting whole coal and steel production of France and Germany under joined management but this organization will be opened for other European states. Schumann's declaration was codified in Paris and came into force in August 10 th 1952 .
• March 25^th 1957.
  Six countries signed the Treaties of Rome, creating the European Atomic Energy Community (EURATOM) and the European Economic Community (EEC). The member states set about removing trade barriers between them and forming a "common market", free flow of people, goods and services and association to Community of colonies and independent territories which are managed by member states.
• July 30^th 1961.
  Applying of common agriculture policy
• 1967.
  The institutions of the three European communities were merged. From this point on, there was a single Commission and a single Council of Ministers as well as the European Parliament.
• July 1^st 1968.
  Six member states abolished mutual trade barriers and adopted common custom policy for the goods that comes outside the borders of EU.
• January 1^st 1973.
  United Kingdom , Denmark , and Ireland become members of EU. Norwegian stays outside Communities because 53.3%.voters voted against membership on the referendum.
• March 13^th 1979.
  The European monetary system ( EMS ) entered into force. EMS provided that all mutual clearings were made in common currency called ECU.
• January 1^st 1981.
  Greece becomes tenth member of Community.
• January 1^st 1986.
  Spain and Portugal become members of Community.
• January 1^st 1987.
  Single European Act came into force. This treaty promotes project Europe 92. SEA represents significant supplement of founding treaties trough amendments. Preamble of SEA sets out basic goal which was creation of European Union.
• February 7^th 1992.
  The Treaty of Maastricht which established the European Union was signed with aim: making easier development of economic and monetary union as well as political.
• January 1993.
  The Treaty of Maastricht came into force.
• January 1994.
  European monetary institute (EMI) was established as a predecessor of European Central Bank but with smaller competences than future Central Bank.
• January 1^st 1995.
  Forth enlargement of EU. Austria , Sweden , and Finland become members of the EU. In Norwegian majority voted again against membership.
• March 25^th 1995.
  The Schengen Agreement came into force. This agreement provided open borders, banned custom inspection between states that signed it and also provided closer police and judicial cooperation.
• December 13^th 1997.
  EU starts process of enlargement for ten new member states from Eastern Europe and Cyprus .
• May 25^th 1998.
  European Commission formally recommended eleven member states to enter into EMU and participate in creation of Euro. These states were Germany , France , Austria , Belgium , Finland , Ireland , Italy , Luxemburg, the Netherlands , Portugal , and Spain.
• January 1^st 1999.
  European Central Bank took over Central monetary government with headquarters in Frankfurt.
• January 4^th 1999.
  Euro becomes single clearing currency in eleven members of EMU. ECU is out of use.
• January 2^nd 2001.
  Greece becomes twelfth member of Euro zone.
• January 1^st 2002.
  Euro becomes official payment currency.
• February 28^th 2002.
  The euro becomes the sole currency within the twelve participating Member States, as the period of dual circulation comes to an end.
• February 1^st 2003.
  Treaty of Nice came into force.
• May 1^st 2004.
  The Accession Treaty enters into force and the European Union's biggest enlargement ever in terms of scope and diversity becomes a reality with 10 new countries - Cyprus , the Czech Republic , Estonia , Hungary , Latvia , Lithuania , Malta , Poland , the Slovak Republic , and Slovenia - representing all together more than 100 million citizens, joining the European Union.
• January 1^st 2007.
  Romania and Bulgaria becomes 26^th and 27^th member state of EU