The predecessor of the European Union (EU) was the European Community (EC for short).
On April 18, 1951, six countries - France, the Federal Republic of Germany, Italy, the Netherlands, Belgium, and Luxembourg - signed the Treaty establishing the European Coal and Steel Community (also known as the Treaty of Paris) in Paris, the capital of France. On July 25, 1952, the European Coal and Steel Community was officially established.
On March 25, 1957, the same six countries - France, the Federal Republic of Germany, Italy, the Netherlands, Belgium, and Luxembourg - signed the treaties aiming to establish the European Economic Community and the European Atomic Energy Community (also known as the Treaty of Rome) in Rome, the capital of Italy. On January 1, 1958, the European Economic Community and the European Atomic Energy Community were officially founded.
On April 8, 1965, these six countries signed the Treaty of Brussels in Brussels, the capital of Belgium, deciding to merge the European Coal and Steel Community, the European Economic Community, and the European Atomic Energy Community, which was collectively referred to as the "European Community".
On July 1, 1967, the Treaty of Brussels took effect, and the EC was officially born.
In 1973, the United Kingdom, Denmark, and Ireland joined the EC.
In 1979, the first direct and democratic elections were held in the European Parliament.
In 1981, Greece joined the EC, becoming the tenth member state of the EC.
In 1986, Portugal and Spain joined the EC, increasing the number of EC member states to 12.
On November 1, 1993, in line with the needs of internal and external development, the EC officially changed its name to the European Union.
In 1995, Austria, Sweden, and Finland joined the EU.
In 2002, euro banknotes and coins replaced the currencies of 12 member states. Since then, the eurozone has expanded to 17 countries.
On November 18, 2002, the foreign ministers of the 15 EU countries held a meeting in Brussels and decided to invite 10 countries, namely Malta, Cyprus, Poland, Hungary, the Czech Republic, Slovakia, Slovenia, Estonia, Latvia, and Lithuania, to join the EU.
On April 16, 2003, at the EU summit held in Athens, the capital of Greece, the above 10 countries officially signed the accession agreement to the EU.
On May 1, 2004, the 10 new member states officially joined the EU.
In October 2004, the leaders of the 25 EU countries signed the Treaty establishing a Constitution for Europe in Rome, the capital of Italy. This was the first constitutional treaty of the EU, aiming to ensure the effective operation of the EU and the smooth progress of the European integration process.
In 2005, France and the Netherlands successively rejected the Treaty establishing a Constitution for Europe in referendums.
On April 25, 2005, Bulgaria and Romania signed the treaty of accession to the EU in Luxembourg. On January 1, 2007, Romania and Bulgaria joined the EU.
In June 2007, the leaders of the 27 countries participating in the EU summit reached an agreement on the draft of a new treaty to replace the Treaty establishing a Constitution for Europe in Brussels. (Note: At this time, there were 27 EU member states, not 28 as the text originally stated before Croatia's accession in 2013)
On December 13, 2007, the leaders of the 27 EU member states reached a consensus on the text of the Treaty of Lisbon in Lisbon, the capital of Portugal, and signed it, submitting it to each member state for ratification.
On June 12, 2008, Irish citizens voted against the Treaty of Lisbon, causing the political integration of the European Union to suffer another setback.
On October 2, 2009, a referendum held in Ireland approved the Treaty of Lisbon (commonly known as the simplified version of the EU Constitution), removing the biggest obstacle to European integration.
On November 3, 2009, Czech President Václav Klaus announced that he had signed the Treaty of Lisbon. By then, all 27 EU member states had approved the treaty.
On November 19, 2009, the leaders of the 27 EU countries held a special summit in Brussels, electing Belgian Prime Minister Herman Van Rompuy as the first Permanent President of the European Council and EU Trade Commissioner Catherine Ashton of the United Kingdom as the High Representative of the Union for Foreign Affairs and Security Policy. The Permanent President of the European Council and the High Representative of the Union for Foreign Affairs and Security Policy were established in accordance with the Treaty of Lisbon adopted on November 3, 2009. According to the characteristics and content of the positions, these two positions are also vividly referred to as the "President of the EU" and the "Foreign Minister of the EU".
On December 1, 2009, the Treaty of Lisbon officially came into force.
On June 17, 2010, the Europe 2020 strategy was adopted at the EU summit, aiming to lead the EU economy out of the debt crisis and enhance its competitiveness.
On July 8, 2010, the plenary session of the European Parliament adopted the plan for the establishment of the EU's "External Action Service". On July 26, the EU Foreign Affairs Council meeting officially adopted the decision on the establishment, structure, and functions of the "External Action Service", marking the official start of the establishment of this new diplomatic institution.
On July 1, 2013, Croatia officially joined the European Union, becoming the 28th member state.
On June 23, 2016, the United Kingdom held a referendum to decide whether the UK should remain in the EU or leave the EU. The Brexit camp won, and the UK will become the first country to leave the EU .
The United Kingdom officially withdrew from the European Union at 11 p.m. (GMT) on January 31, 2020.