The beginning of the end

Jan 23, 2013. Under pressure from his Conservative party (the Tories) and in an effort to dissuade voters from flocking to the anti-European Union UKIP party, Prime Minister David Cameron puts his political future on the line and says he intends to hold an in/out referendum on the UK's EU membership.

May 7, 2015. Cameron's Conservatives win the general election. Their manifesto includes a pledge to hold an EU referendum.

June 23, 2016. By the narrowest of margins, 51.9% vote to leave, 48.1% to remain in the referendum. Cameron resigns a day later as prime minister.

Brexit — come what May

July 13. Former Home Secretary Theresa May wins the Tories' leadership contest and becomes prime minister. In a speech, she utters the now infamous words "Brexit means Brexit," essentially tying her fate to the success or otherwise of the Brexit process.

July 27. Michel Barnier, a former EU commissioner and French foreign minister, is appointed as lead negotiator for the EU.

March 29, 2017. May triggers Article 50 of the Treaty of European Union that sets in motion the process of the UK leaving the EU on March 29, 2019.

May 2017. The European Commission presents its negotiating framework. Financial settlement, citizens' rights and arrangements for the Irish border are some of the key issues of the divorce talks.

Snap out of it

June 8. Seeking to cement her party's power and bolster her bargaining hand with the EU, May calls a snap election. Her plan backfires and she loses her majority in Parliament, forcing her into a deal with the Northern Irish Democratic Unionist Party (DUP) to remain in power.

June 19. Brexit Secretary David Davis arrives in Brussels to officially kick off talks with Michel Barnier. Davis and his team become the focus of much derision after a photo shows them sitting at a table empty-handed while their EU counterparts look prepared with large piles of papers in front of them.

December 13. Rebel Tory Members of Parliament (MPs) side with the Labour opposition, forcing the government to guarantee a vote on the final Brexit deal.

December 15. The EU agrees to move on to the second phase of negotiations after an agreement is reached on the financial settlement, the Irish border, and EU citizens' rights. One of the most contentious issues regarding the Irish border is a so-called backstop, intended to guarantee there will not be a hard border between Northern Ireland and the Republic of Ireland, even if no deal can be reached on trade and security arrangements.

The unknown unknowns

March 2, 2018. After weeks of deadlock, May hints at more compromise in areas such as fishing rights, European Court of Justice jurisdiction, and freedom of movement.

March 9. Negotiations gather pace. Agreements include dates for a transitional period after Brexit day, the status of EU citizens in the UK before and after that time and fishing policy. The Irish border issue remains a stumbling block.

July 6. May presents her plan to her cabinet. It builds on her outline of "managed divergence" from EU rules, but several leading Tory members accuse her of selling out and opting for a much softer Brexit. David Davis resigns in protest, followed by Foreign Minister Boris Johnson. By the end of the year, 18 Tories will have quit over Brexit.

September 21. An EU summit turns into a disaster for May as EU leaders accuse May of "cherry-picking" the best conditions for the UK from EU rules. European Council President Donald Tusk warns her that she risks "undermining the single market."

November 25. At an EU summit, the UK and the EU strike a deal on the exit process, subject to the approval by the UK Parliament and European parliaments. Another obstacle is removed after May tweaks her proposal to include a customs union with the EU to solve the controversial Irish backstop issue.

Mayday, Mayday

December 13. May's deal with the EU triggers a fierce backlash within her party. She survives a vote of no confidence, but her days in office look increasingly numbered.

January 15, 2019. May's government is dealt a humiliating blow as it loses the first meaningful vote on the EU-UK deal.

January 30. With her tail between her legs, May is sent scurrying back to Brussels to negotiate "alternative" arrangements to the Irish backstop.

March 12. Behind the scenes, frantic efforts by the government to modify the deal go nowhere after the attorney-general says the revised arrangement will not guarantee the UK can unilaterally get out of the backstop. The government subsequently loses the second meaningful vote.

March 20. With the official exit day approaching fast, Parliament forces May's hand to ask the EU for an extension and delay Brexit from March 29 until June 30. EU leaders are not impressed and instead offer her two alternatives: May 22 if the deal is passed, April 13 if not.

March 29. The government loses a third meaningful vote. The situation becomes even more intractable as attempts fail to find a majority for an alternative solution, such as a second referendum.

April 10/11. With options running out, May requests yet another delay. EU leaders agree to a "flexible" extension until Oct 31 with the possibility of the UK leaving earlier if it can get the deal through Parliament.

May 24. May announces her decision to step down on June 7, bringing her three-year tenure to an end. The final nail in the coffin was the rejection across the political spectrum of her new 10-point plan, which controversially included an offer of a binding vote on a referendum if the deal passes.

Mr. Johnson goes to Brussels

July 23. Boris Johnson wins the Tory leadership contest and becomes the new prime minister.

August 19. Johnson formally asks the EU to drop the Irish backstop mechanism from the Withdrawal Agreement (WA). EU leaders reject the idea.

August 28. Parliament is prorogued, or suspended, for five weeks. Johnson rejects accusations of using a transparent ploy to prevent MPs from derailing his Brexit plans.

September 3. 21 rebel Tories vote against the government's Brexit strategy to leave the EU on October 31 with or without a deal. They are expelled from the party.

September 9. The so-called Benn bill (named after the Labour MP Hilary Benn) comes into law, effectively preventing the UK from leaving the EU without parliamentary approval.

September 24. The UK's Supreme Court rules that the suspension of Parliament was unlawful. The House of Commons resumes business.

October 8. A flurry of activity goes nowhere fast and talks break down amid much mudslinging from both sides.

October 17. Events take a dramatic turn after the EU and the UK announce they've struck a new deal after Johnson makes new concessions on the Irish border issue to replace the backstop. Under the new protocol, the UK maintains an open border with the Republic of Ireland, which means EU-UK checks on goods will take place at a de facto border down the Irish Sea.

Trying to be flexible

October 19. MPs throw a spanner in the works and withhold their approval until the laws implementing Brexit go into effect.

October 28. After MPs force Johnson to seek yet another extension, the EU offers the UK a "flextension" until January 31, 2020.

December 1. Ursula von der Leyen replaces Jean-Claude Juncker as EU Commission president, while Charles Michel takes over from Donald Tusk as European Council leader.

December 12. Johnson wins the snap election he called for in October in an attempt to break the parliamentary impasse. His Tories gain a massive 80-seat majority.

Just when you thought it was over

Jan 23, 2020. The UK's WA bill eases through Parliament and becomes law.

Jan 29. The European Parliament gives its green light for the divorce bill.

Jan 31. The UK officially leaves the EU.

Feb 1. An 11-month transition period begins and will end on Dec. 31, 2020.  During that time, the UK remains part of the single market and the customs union. The UK forfeits voting rights, but must continue to follow EU rules during this period. The idea behind the transition is to allow both sides to finalize details of a future UK-EU relationship.

March 2. The first round of talks on the future relationship take place.

April 15. The coronavirus pandemic puts meaningful progress on hold. However, Barnier and his UK counterpart, David Frost, agree on restarting a restricted version of the talks.

June 30/July 1. A pivotal date of the process. Johnson lets the legal deadline for the UK to seek a transition extension pass by. Arguably even more crucial is the missed deadline to find an agreement on fishing rights for EU fishermen in UK waters. This issue will haunt the subsequent talks and thwart any meaningful progress.

September 6. All hell breaks loose after reports emerge that the UK is looking into new legislation that would quash parts of the WA relating to the Northern Irish backstop. The EU Commission launches legal action. EU member states say the move not only breaches international law but also threatens the Good Friday peace accord that ended the Troubles in Northern Ireland.

Will it end in tears?

Oct 16. Johnson suspends the future relationship talks, arguing that the EU is not being serious and fair. Talks can only resume, he says, if there is a "fundamental" change in the EU's approach. At an EU summit, EU leaders urge compromises on both sides but remain adamant that the EU will not budge on vital interests, notably fishing rights and fair competition rules.

Dec. 13. With a no-deal scenario looming large, a self-imposed deadline on reaching a deal comes and goes. Following a flurry of frantic meetings and phone calls, both sides agree to "go the extra mile" in an effort to conjure up a breakthrough.

Dec 31. Once the clock strikes midnight in Brussels, the transition period ends and the UK officially leaves the single market and the customs union. At this stage, it's still unclear whether future trade between the EU and the UK will follow a tariff-free and quota-free system or whether World Trade Organization rules apply (tariffs and taxes would be levied on goods trading between the UK and the EU).

What is beyond doubt is that even if a deal is reached, there will be major disruptions to trade as new border arrangements come into force.