The Roman Empire in AD 117, at its greatest extent (with its vassals
During the centuries following the fall of Rome in 476, several European States viewed themselves as translatio imperii ("transfer of rule") of the defunct Roman Empire: the Frankish Empire (481–843) and the Holy Roman Empire (962–1806) were thereby attempts to resurrect Rome in the West.[f] This political philosophy of a supra-national rule over the continent, similar to the example of the ancient Roman Empire, resulted in the early Middle Ages in the concept of a renovatio imperii ("restoration of the empire"), either in the forms of the Reichsidee ("imperial idea") or the religiously inspired Imperium Christianum ("christian empire"). Medieval Christendom and the political power of the Papacy are often cited as conducive to European integration and unity.
In the oriental parts of the continent, the Russian Tsardom, and ultimately the Empire (1547–1917), declared Moscow to be Third Rome and inheritor of the Eastern tradition after the fall of Constantinople in 1453. The gap between Greek East and Latin West had already been widened by the political scission of the Roman Empire in the 4th century and the Great Schism of 1054; and would be eventually widened again by the Iron Curtain (1945–91).
Pan-European political thought truly emerged during the 19th century, inspired by the liberal ideas of the French and American Revolutions after the demise of Napoléon's Empire (1804–15). In the decades following the outcomes of the Congress of Vienna, ideals of European unity flourished across the continent, especially in the writings of Wojciech Jastrzębowski, Giuseppe Mazzini or Theodore de Korwin Szymanowski. The term United States of Europe (French: États-Unis d'Europe) was used at that time by Victor Hugo during a speech at the International Peace Congress held in Paris in 1849:
A day will come when all nations on our continent will form a European brotherhood ... A day will come when we shall see ... the United States of America and the United States of Europe face to face, reaching out for each other across the seas.
During the interwar period, the consciousness that national markets in Europe were interdependent though confrontational, along with the observation of a larger and growing US market on the other side of the ocean, nourished the urge for the economic integration of the continent. In 1920, advocating the creation of a European economic union, British economist John Maynard Keynes wrote that "a Free Trade Union should be established ... to impose no protectionist tariffs whatever against the produce of other members of the Union." During the same decade, Richard von Coudenhove-Kalergi, one of the first to imagine of a modern political union of Europe, founded the Pan-Europa Movement. His ideas influenced his contemporaries, among which then Prime Minister of France Aristide Briand. In 1929, the latter gave a speech in favour of a European Union before the assembly of the League of Nations, precursor of the United Nations. In a radio address in March 1943, with war still raging, Britain's leader Sir spoke warmly of "restoring the true greatness of Europe" once victory had been achieved, and mused on the post-war creation of a "Council of Europe" which would bring the European nations together to build peace.
After World War II, European integration was seen as an antidote to the extreme nationalism which had devastated parts of the continent. In a speech delivered on 19 September 1946 at the University of Zürich, Switzerland, Winston Churchill went further and advocated the emergence of a United States of Europe. The 1948 Hague Congress was a pivotal moment in European federal history, as it led to the creation of the European Movement International and of the College of Europe, where Europe's future leaders would live and study together.
It also led directly to the founding of the Council of Europe in 1949, the first great effort to bring the nations of Europe together, initially ten of them. However, the Council focused primarily on values—human rights and democracy—rather than on economic or trade issues, and was always envisaged as a forum where sovereign governments could choose to work together, with no supra-national authority. It raised great hopes of further European integration, and there were fevered debates in the two years that followed as to how this could be achieved.
But in 1952, disappointed at what they saw as the lack of progress within the Council of Europe, six nations decided to go further and created the European Coal and Steel Community, which was declared to be "a first step in the federation of Europe". This community helped to economically integrate and coordinate the large number of Marshall Plan funds from the United States. European leaders Alcide De Gasperi from Italy, Jean Monnet and Robert Schuman from France, and Paul-Henri Spaak from Belgium understood that coal and steel were the two industries essential for waging war, and believed that by tying their national industries together, future war between their nations became much less likely. These men and others are officially credited as the founding fathers of the European Union.
Treaty of Rome (1957–92)
The continental territories of the member states of the European Union (European Communities pre-1993), coloured in order of accession
In 1957, Belgium, France, Italy, Luxembourg, the Netherlands, and West Germany signed the Treaty of Rome, which created the (EEC) and established a customs union. They also signed another pact creating the (Euratom) for co-operation in developing nuclear energy. Both treaties came into force in 1958.
The EEC and Euratom were created separately from the ECSC, although they shared the same courts and the Common Assembly. The EEC was headed by Walter Hallstein (Hallstein Commission) and Euratom was headed by Louis Armand (Armand Commission) and then Étienne Hirsch. Euratom was to integrate sectors in nuclear energy while the EEC would develop a customs union among members.
During the 1960s, tensions began to show, with France seeking to limit supranational power. Nevertheless, in 1965 an agreement was reached and on 1 July 1967 the Merger Treaty created a single set of institutions for the three communities, which were collectively referred to as the European Communities. Jean Rey presided over the first merged Commission (Rey Commission).
In 1973, the Communities were enlarged to include Denmark (including Greenland, which later left the Communities in 1985, following a dispute over fishing rights), Ireland, and the United Kingdom. Norway had negotiated to join at the same time, but Norwegian voters rejected membership in a referendum. In 1979, the first direct elections to the European Parliament were held.
Greece joined in 1981, Portugal and Spain following in 1986. In 1985, the Schengen Agreement paved the way for the creation of open borders without passport controls between most member states and some non-member states. In 1986, the European flag began to be used by the EEC and the Single European Act was signed.
In 1990, after the fall of the Eastern Bloc, the former East Germany became part of the Communities as part of a reunified Germany. A close fiscal integration with the introduction of the euro was not matched by institutional oversight making things more troubling. Attempts to solve the problems and to make the EU more efficient and coherent had limited success.
Maastricht Treaty (1992–2007)
was introduced in 2002, replacing 12 national currencies. Seven countries have since joined.
The European Union was formally established when the Maastricht Treaty—whose main architects were Helmut Kohl and François Mitterrand—came into force on 1 November 1993. The treaty also gave the name to the EEC, even if it was referred as such before the treaty. With further enlargement planned to include the former communist states of Central and Eastern Europe, as well as Cyprus and Malta, the Copenhagen criteria for candidate members to join the EU were agreed upon in June 1993. The expansion of the EU introduced a new level of complexity and discord. In 1995, Austria, Finland, and Sweden joined the EU.
In 2002, euro banknotes and coins replaced national currencies in 12 of the member states. Since then, the eurozone has increased to encompass 19 countries. The euro currency became the second largest reserve currency in the world. In 2004, the EU saw its biggest enlargement to date when Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia joined the Union.
Lisbon Treaty (2007–present)
In 2007, Bulgaria and Romania became EU members. The same year, Slovenia adopted the euro, followed in 2008 by Cyprus and Malta, by Slovakia in 2009, by Estonia in 2011, by Latvia in 2014, and by Lithuania in 2015.
On 1 December 2009, the Lisbon Treaty entered into force and reformed many aspects of the EU. In particular, it changed the legal structure of the European Union, merging the EU three pillars system into a single legal entity provisioned with a legal personality, created a permanent President of the European Council, the first of which was Herman Van Rompuy, and strengthened the position of the High Representative of the Union for Foreign Affairs and Security Policy.
In 2012, the EU received the Nobel Peace Prize for having "contributed to the advancement of peace and reconciliation, democracy, and human rights in Europe." In 2013, Croatia became the 28th EU member.
From the beginning of the 2010s, the cohesion of the European Union has been tested by several issues, including a debt crisis in some of the Eurozone countries, increasing migration from the Middle East, and the United Kingdom's withdrawal from the EU. A referendum in the UK on its membership of the European Union was held in 2016, with 51.9% of participants voting to leave. The UK formally notified the European Council of its decision to leave on 29 March 2017, initiating the formal withdrawal procedure for leaving the EU, committing the UK in principle to leave the EU two years later, on 29 March 2019, unless an extension was sought and granted, which occurred.
The following timeline illustrates the integration that has led to the formation of the present union, in terms of structural development driven by international treaties:
The criteria for accession to the Union are included in the Copenhagen criteria, agreed in 1993, and the Treaty of Maastricht (Article 49). Article 49 of the Maastricht Treaty (as amended) says that any "European state" that respects the "principles of liberty, democracy, respect for human rights and fundamental freedoms, and the rule of law", may apply to join the EU. Whether a country is European or not is subject to political assessment by the EU institutions.
There are five recognised candidates for future membership of the Union: Turkey (applied on 14 April 1987), North Macedonia (applied on 22 March 2004 as "Former Yugoslav Republic of Macedonia"), Montenegro (applied in 2008), Albania (applied in 2009), and Serbia (applied in 2009). While the others are progressing, Turkish talks are at an effective standstill.