Britain will leave the European Union on Friday and end almost half a century of integration, starting a new chapter in its history. At midnight in Brussels (23:00 GMT), Britain will become the first country to leave the 28-member bloc since 1973.
Prime Minister Boris Johnson backed Brexit through the 2016 referendum vote to leave but since coming to Downing Street has promised to unite the country in a new era of prosperity.
Official celebrations will not go ahead out of respect for half of the population which wanted to stay in the EU and who remain fearful of what lies ahead.
"Our job as the government, my job, is to bring this country together and take us forward," Johnson said in a statement.
"This is not an end but a beginning. This is the moment when the dawn breaks and the curtain goes up on a new act."
Nothing will feel immediately different, as there is an 11-month transition period which was negotiated as part of an EU-UK exit deal ratified this week.
Britons will be able to work in and trade freely with EU nations until December 31, and vice versa, although the UK will no longer be represented in the bloc's institution.
But legally, Britain is out of the EU.
Whilst the exit terms have been agreed, it must still strike a deal on future relations with the EU, which is Britain's largest trading partner.
"We will remain friends, allies and partners," Michel Barnier, the EU's chief negotiator told the BBC. He also said that his thoughts were with "the millions of British citizens who are sad, as we are sad."
Britons still remain as divided as they were four years ago, when 52 percent voted to leave and 48 percent voted to remain in the EU.
Johnson will hold a cabinet meeting in the northeastern English city of Sunderland, which was the first to declare for Brexit in the 2016 vote.
At 22:00 GMT, he will broadcast an address to the nation, followed by a reception for staff at Downing Street.
A light show will be held outside No 10, while millions of commemorative 50 pence coins are being minted to mark the occasion.
Ex-MEP Nigel Farage, who has spent decades campaigning to leave the EU, is planning a large rally in nearby Parliament Square. He delivered a speech on Wednesday, which was his last day as a member of the European Parliament, waving Union Jack flags and saying that Britain "was never coming back."
Many MEPs said goodbye to Britain by breaking out into a chorus of the traditional Scottish song of farewell, "Auld Lang Syne."
On Thursday, Brussels' Grand-Place was lit in red, white and blue.
Johnson has given himself 11 months to negotiate a new partnership, which covers areas including trade and security cooperation. He set out his plans in a speech on Monday but Brussels has already warned that he must limit his ambitions or ask for more time.
Johnson also has plans to strike a trade deal with the U.S. During a visit to London on Thursday, American Secretary of State, Mike Pompeo said: "You will see the enormous benefits that accrue to both of our nations as a result of this."