February 20, 2016: David Cameron announces the date for the referendum on whether to leave the EU.
June 23, 2016: The UK votes to leave the EU.
July 13, 2016: Theresa May becomes PM after seeing off challenges from Boris Johnson and Michael Gove.
March 29, 2017: Mrs May formally notifies the EU that the UK is triggering the Article 50 process for leaving the bloc.
June 8, 2017: The Tories lose their majority in the snap election called by Mrs May in a bid to strengthen her hand on Brexit. Mrs May manages to stay in power propped up by the DUP.
November 2018: Mrs May finally strikes a Withdrawal Agreement with the EU, and it is approved by Cabinet – although Esther McVey and Dominic Raab resign.
December 2018: Mrs May sees off a vote of no confidence in her leadership triggered by Tory MP furious about her Brexit deal.
January 15-16, 2019: Mrs May loses first Commons vote on her Brexit deal by a massive 230 votes. But she sees off a Labour vote of no confidence in the government.
March 12, 2019: Despite tweaks following talks with the EU, Mrs May’s deal is defeated for a second time by 149 votes.
March 29, 2019: Mrs May’s deal is defeated for a third time by a margin of 58 votes.
May 24, 2019: Mrs May announces she will resign on June 7, triggering a Tory leadership contest.
July 23-24, 2019: Mr Johnson wins the Tory leadership, becomes PM and eventually strikes a new deal with the EU.
October 22, 2019: MPs approve Mr Johnson’s deal at second reading stage in a major breakthrough – but they vote down his proposed timetable and vow to try to amend the Bill later. The PM responds by pausing the legislation and demands an election.
October 29, 2019: MPs finally vote for an election, after the SNP and Lib Dems broke ranks to vote in favour, forcing the Labour leadership to agree.
December 12, 2019: The Tories win a stunning 80 majority after vowing to ‘get Brexit done’ during the campaign. Jeremy Corbyn’s Labour records its worst performance since 1935 after he sits on the fence over Brexit, saying there should be a second referendum and he wants to remain neutral.
December 20, 2019: The new-look Commons passes Mr Johnson’s Withdrawal Bill by a majority of 124.
January 9: EU Withdrawal Agreement Bill cleared its Commons stages, and was sent to the House of Lords.
January 22: The EU Withdrawal Bill completed its progress through Parliament after the Commons overturned amendments tabled by peers, and the Lords conceded defeat.
January 24: Mr Johnson signs the ratified Withdrawal Agreement in another highly symbolic step.
January 29: MEPs approve the Withdrawal Agreement by 621 to 49. Amid emotional scenes in Brussels, some link hands to sing a final chorus of Auld Lang Syne.
11pm, January 31: The UK formally leaves the EU – although stays bound to the bloc’s rules for at least another 11 months during the transition period.
March 5: The first round of trade talks between the UK and the EU conclude.
June 30: Downing Street denies the option of extending the Brexit transition period as Mr Johnson repeatedly insists it will end on December 31, with or without a trade deal.
August 21: Michel Barnier says talks have actually gone ‘backwards’ after months of negotiating deadlock as both sides concede a deal appears unlikely.