European integration is the process of industrial, political, legal, economic, social and cultural integration of states wholly or partially in Europe. European integration has primarily come about through the European Union and its policies.
One of the first to conceive of a union of European nations was Richard von Coudenhove-Kalergi, who wrote the Pan-Europa manifesto in 1923. His ideas influenced Aristide Briand, who gave a speech in favour of a European Union in the League of Nations on 8 September 1929, and who in 1930 wrote a "Memorandum on the Organization of a Regime of European Federal Union" for the Government of France, which became the first European government formally to adopt the principle.
Winston Churchill
At the end of World War II, the continental political climate favoured unity in democratic European countries, seen by many as an escape from the extreme forms of nationalism which had devastated the continent. In a speech delivered on 19 September 1946 at the University of Zürich, Switzerland, Winston Churchill postulated a United States of Europe. The same speech however contains remarks, less often quoted, which make it clear that Churchill did not initially see Britain as being part of this United States of Europe: We British have our own Commonwealth of Nations ... And why should there not be a European group which could give a sense of enlarged patriotism and common citizenship to the distracted peoples of this turbulent and mighty continent and why should it not take its rightful place with other great groupings in shaping the destinies of men? ... France and Germany must take the lead together. Great Britain, the British Commonwealth of Nations, mighty America and I trust Soviet Russia-for then indeed all would be well-must be the friends and sponsors of the new Europe and must champion its right to live and shine.
The question of how to avoid wars between the nation-states was essential for the first theories. Federalism and Functionalism proposed the containment of the nation-state, while Transactionalism sought to theorise the conditions for the stabilisation of the nation-state system.