The European Union is built on a series of Treaties. Each one is signed by the governments of the participating countries and by signing these treaties they agree to cooperate and be part of the EU.
There are Foundation Treaties and Accession Treaties.
Accession Treaties are made when new countries join the EU. See here for more information about the Enlargement of the EU.
The Founding Treaties are made when the countries in the EU want to increase the amount of powers and tasks they want to share.
The earliest of these treaties was the treaty establishing theEuropean Coal and steel community signed in Paris in 1951 followed by the Treaty of Rome signed in 1957 which is generally regarded as the first of the EU treaties (shown in the picture).
See below for the most important EU treaties, starting with the most recent.
The Lisbon Treaty
The Lisbon Treaty was signed in 2007 and came into force in 2009.
This is one of the most important of the EU treaties.
It tidied up all the earlier treaties but it also added some new bits. In particular –
A new President of the European Council
A new ‘Head of Foreign Affairs’ – the correct title is ‘The High Representative for Common foreign and Security Policy’
It added the Citizens Initiative
It made practical changes to the running of the EU
It included the Charter of Fundamental Rights
The Treaty of Nice
The Treaty of Nice was signed in 2001 and came into force in 2003.
This treaty focused on reforming some of the EU procedures to make it easier to allow more members to join. It prepared the way for the Eastern European Countries to join the EU.
The Nice treaty also broadened the use of QMV (Qualified Majority Voting) in the Council of the European Union.
The Amsterdam Treaty
The Amsterdam treaty was signed in 1997 and came into force in 1999.
The Ansterdam Treaty is often called ‘the People’s Treaty’. This is because it included a lot of new areas like protecting the environment, promoting equality and about working conditions and more employment.
The Maastricht Treaty
The Maastricht Treaty was signed in 1992 and came into force in 1993. The full title is the Treaty on European Union (TEU).
The responsibilities of the EU were divided into three categories – these were described as pillars, and in the end people just called them ‘the three pillars’.
From now on the EU has its name – the European Union
The First pillar
This covered everything to do with the economy, also the environment and social policies.
Decisions were made using QMV and The Ordinary Legislative Procedure – but at this time it was called Co-Decision. This is called the Community Method.
The Second Pillar and Third Pillar
These were different to the First Pillar because they made decisions without using the Community Method. These covered the sensitive areas of Security and Foreign Policy (CSFP) and Justice (JHA) and governments didn’t want to share power on these.
The Second Pillar was CSFP and the Third Pillar was JHA.
The Single European Act
The Single European Act is also a treaty. It came into force in 1987. This is one of the most important treaties of the EU.
This treaty is all about the economy and making the EU work better. In particular, the SEA helped to complete the Single Market.
This treaty also included the idea that weaker countries in the EU should be given aid and funding to help them to catch up with the average standard of living in the EU – this was called the ‘Cohesion policy’.
The Treaties of Rome
The Treaty of Rome was signed in 1957 and came into force in 1958. It was the treaty that established the EEC – the European Economic Community.
This is the one that is generally regarded as the first EU treaty.
The Euratom Treaty was signed in 1957 and came into force in 1958. this treaty established the European Atomic Energy Community.
Because they were signed at the same time they are known together as the Treaties of Rome.
If you would like to read a treaty
The treaties are available online for anyone to read. See below for some useful links. Remember these are legal documents so they are very formal and precise. Have a look just to see what a treaty looks like.
These are published on Eur-Lex which is the official EU website for all EU Law.
For the Lisbon Treaty see here