As the UK leaves the EU at 11pm on Friday, the Queen will be at Sandringham, her private estate in Norfolk, where she is spending her annual winter break.
The monarch has already given Royal Assent to the legislation for Boris Johnson’s Brexit deal, which the Prime Minister hailed as crossing the “Brexit finish line”.
She is not expected to make a statement to the nation regarding Brexit.
On Brexit Day, the Queen, as on every other day, will be dealing with official documents, such as Cabinet and State papers, delivered to her in her famous “red boxes”.
She may also be sending birthday wishes to her distant cousin Princess Beatrix of the Netherlands, formerly Queen Beatrix, who celebrates turning 82 on January 31.
The Queen missed her annual visit to the local Women’s Institute last week because of a cold, but was back at church on Sunday.
She has been dealing with the uncharted territory of “Megxit” with the Duke and Duchess of Sussex preparing to drop their HRH styles and quit the monarchy, and also faced the Duke of Edinburgh being hospitalised for four night before Christmas.
The monarch was dragged into a constitutional row during her summer holidays in August 2019 amid Westminster’s bitter Brexit battles when Mr Johnson asked her to suspend Parliament for more than a month.
The sovereign was duty bound to hold a Privy Council meeting at Balmoral, her private Scottish estate, where, acting on the advice of the PM, she approved an order to temporarily close – or prorogue – parliament for five weeks.
Opposition leaders wrote to the Queen in protest and Commons Speaker John Bercow said the move was a “constitutional outrage” designed to stop Parliament debating Brexit.
In the end, the Supreme Court ruled that Mr Johnson’s advice to the Queen to suspend Parliament was unlawful because it had the effect of frustrating Parliament.
During the 2017 State Opening of Parliament, the Queen’s speech, written by the Government, laid out the Brexit legislation that the Government intended to pass during the parliamentary session.
Some suggested that the monarch’s hat, which was blue with yellow floral details, resembled the EU flag.
But the Queen’s senior dresser Angela Kelly, who designed the piece with milliner Stella McLaren, later insisted it was not a coded message.
“It never occurred to Stella and me that people might think we were copying the European Union flag,” she wrote in her memoirs.
“It was a coincidence but, boy, did it attract a lot of attention, and it certainly made us smile.”
As head of state, the Queen remains publicly neutral when it comes to political matters.
But commentators saw her words in 2019 as a nod to the toxic mood of the public debate around Britain leaving the EU.
In a speech to mark the centenary of the Sandringham Women’s Institute (WI), she spoke in favour of individuals seeking “common ground” and “never losing sight of the bigger picture” in what was interpreted as a veiled reference to Brexit.
The monarch extolled the virtues of “respecting” the other person’s point of view.
She has also used her Christmas messages in recent years to allude to differences and call for greater understanding.
In 2019, she acknowledged the “bumpy” path her family and the country had experienced during the past 12 months.
She said the Christmas message of peace and goodwill still had relevance and was a reminder of what can be achieved when people abandon their differences and “come together in the spirit of friendship and reconciliation”.
The head of state writes her Christmas Day broadcast herself and it is one of the rare occasions when she does not turn to the Government for advice and is able to voice her own views.
During a state visit by King Willem-Alexander of the Netherlands in October 2018, the Queen spoke publicly about Brexit for the first time, telling the King that “as we look toward a new partnership with Europe” the values shared by the UK and Holland “are our greatest assets”.
During the referendum campaign in 2016, a major row broke out over a front-page story that stated the Queen supported EU withdrawal.
The Sun’s report said an anonymous source had told the paper she had voiced strong Eurosceptic views during a lunch in 2011 with the then-deputy prime minister Nick Clegg.
The former Liberal Democrat leader later said the suggestion the Queen had given him a “tongue lashing” about Europe was “preposterous”.
Mr Clegg, now Sir Nick, said then-justice secretary Michael Gove was behind the story, but Mr Gove has never confirmed the allegation.
Buckingham Palace complained to the press watchdog Ipso over the “Queen backs Brexit” front page.
Ipso later upheld the complaint and ruled the headline was inaccurate, although The Sun stood by its article.
BBC political editor Laura Kuenssberg later said she had also been told that the Queen supported Brexit, but did not report it as she could not find a second source to corroborate the claim.
In February 2019, The Sunday Times said that Whitehall was drawing up secret plans to evacuate the Queen and other senior royals from London in the event of riots triggered by a no-deal Brexit.
The newspaper said the emergency proposals had been re-purposed from those originally formulated during the Cold War in the event of a nuclear attack by the Soviet Union.