After 44 years, it's over: Historic moments in the EU-UK relationship

On Wednesday, Britain made the historic move of becoming the first nation to ever leave the European Union, following a vote on membership in 2016.

Prime Minister Theresa May officially gave notification to the EU with a letter triggering Article 50 of the Lisbon Treaty, and kicking off a two-year negotiating period.

The 44-year-old relationship has been put to the test many times - here, we look back at the significant moments in the often difficult, historic bond we have had with the EU.

  • 1973 - Britain joins the European Economic Community (EEC)

Throughout the 60s and 70s, Britain was desperate to get into the EEC and spent years trying to convince France to let them in.

France, under Charles de Gaulle, was experiencing a renaissance, and in 1963 vetoed the decision to let Britain into the EEC, saying, "England is not much any more". And he did it again in 1967.

Finally, in 1973, with de Gaulle out of the way, Britain joined the EEC, along with Ireland and Denmark.

British Prime Minister Edward Heath said: "From the point of view of our everyday lives we will find there is a great cross-fertilisation of knowledge and information, not only in business but in every other sphere.

"And this will enable us to be more efficient and more competitive in gaining more markets not only in Europe but in the rest of the world."

  • 1975 - Britain votes to stay in the EEC

The 1975 referendum on membership of the Common Market Credit: PA

British voters backed the UK's continued membership of the EEC, by a clear majority of 67%.

The voters supported the Labour government's campaign to stay in the Common Market despite several cabinet ministers saying withdrawal is best.

The result was hailed by Prime Minister Harold Wilson as a "historic decision".

  • 1984 - Margaret Thatcher secures permanent rebate for the UK

Margaret Thatcher campaigning to remain inside the Common Market in 1975 Credit: PA

In 1980, some 70% of the EU's budget was spent on the Common Agricultural Policy (CAP), which did not benefit the UK.

The UK therefore soon became a large net contributor to the EU budget, even though it was the third-poorest member at the time.

In June 1984, Margaret Thatcher negotiated the UK rebate, which was ratified and implemented in May 1985.

  • 1992 - Maastricht Treaty signed

In February 1992, John Major signed the Maastricht Treaty which further integrated EU countries politically.

It gave the EU new responsibilities to create common foreign and security policy and for home and judicial affairs - such as asylum, immigration, drugs and terrorism.

The treaty was seen as a compromise between a full union and a more looser arrangement which the UK wanted.

Signing the deal, Major ensured that Britain opted out of the new social chapter, which concerned workers' rights and pay.

  • 1992 - Black Wednesday

On 16 September 1992, the conservative government under John Major was forced to withdraw the pound sterling from the European Exchange Rate Mechanism (ERM) after it could not keep the pound above its agreed lower limit.

Then-Chancellor Norman Lamont said the government had done all it could to prop up the depreciating pound, but at an emergency meeting, he and the Prime Minister agreed they should withdraw from the ERM, which pushed the UK into a recession.

  • 1997 - Tony Blair signed social chapter of Maastricht Treaty

The treaty was originally signed in 1992 by John Major without the social chapter - which impacts on workers' rights and pay.

Tony Blair signed the social chapter section of the treaty in 1997.

  • 1999 - Euro launches, without British participation

On January 1 1999, the single currency was born. It was adopted by 15 EU member states excluding the UK, Sweden and Denmark. Greece was initially excluded because of its weak economy but joined in 2001.

  • 2011 - David Cameron vetoes EU-wide deal to tackle Euro crisis

Britain became the only EU-member state to resist a so-called "Tobin tax" - a financial transactions tax - to tackle the eurozone crisis.

  • 2013 - David Cameron promises renegotiation and referendum

In January 2013, David Cameron promised in a speech that if the Conservatives were voted into power in 2015, he would go to the EU to try to renegotiate some of the terms of the relationship.

Then, having done that, he said he would give the choice over to the British people, and ask them whether they like the new terms or whether they want to leave altogether.

  • 2016 - UK votes to leave the EU

Leave campaigners, including Nigel Farage, celebrate the referendum win Credit: PA

On the 23 June 2016, the referendum was held and the UK voted to leave the European bloc.

The margin was narrow - 52% voted to leave, while 48% voted to stay.

The next day, Prime Minister David Cameron resigned and after a short leadership election, Theresa May took over.

  • 2017 - Start of formal negotiations begins with Article 50 notification

Sir Tim Barrow - UK ambassador to the EU - delivers a letter to Donald Tusk, President of the European Council, to trigger Article 50. Credit: Twitter

Sir Tim Barrow, UK ambassador to the EU, delivers a letter to Donald Tusk, President of the European Council, to trigger Article 50.

The letter is from the Prime Minister and sets out that Britain intends to leave the European Union.