A sombre-looking Charles III today paid tribute to his 'darling mother' in a rare address to both Houses of Parliament.
The new King said he felt the "weight of history" as he spoke to hundreds of MPs and peers in Westminster Hall, where the Queen will lie in state from Wednesday under its 14th Century hammer-beam roof.
Paying tribute to his mother, he said: "She set an example of selfless duty which, with God's help and your counsels, I am resolved faithfully to follow."
After the speech he looked visibly moved as God Save the King was sung formally in his presence for the first time.
During his speech King Charles highlighted the Big Ben bell - which hangs in the Elizabeth Tower named for his mother, and will toll for her coffin's procession to Westminster - as "one of the most powerful symbols of our nation throughout the world".
He went on: “The tangible connections to my darling late mother we see all around us, from the fountain in New Palace Yard which commemorates the late Queen’s silver jubilee, to the sundial in Old Palace Yard for the golden jubilee.
"The magnificent stained glass window before me for the diamond jubilee and so poignantly, and yet to be formally unveiled, your most generous gift to her late Majesty to mark the unprecedented Platinum Jubilee which we celebrated only three months ago with such joyful hearts.”
The King recalled how Shakespeare described Elizabeth I as “a pattern to all princes living“.
He added: "As I stand before you today I cannot help but feel the weight of history which surrounds us and which reminds us of the vital Parliamentary traditions to which members of both Houses dedicate yourselves with such personal commitment for the betterment of us all."
After vowing to give up his sometimes controversial campaigning as the monarch, he said: "Parliament is the living and breathing instrument of our democracy."
In an address to the new King, Commons Speaker Lindsay Hoyle said "this is a loss that is felt around the world", adding: "It is a loss to all of us - but we know most of all it is a loss to you, your Majesty.”
The Speaker hailed Elizabeth II's "duty, wisdom, kindness and humour", to which the new King said he was "deeply grateful".
And he told how the Queen stood in the same spot in 1988 to mark 300 years since the Glorious Revolution. Charles smiled - or grimaced - as the Speaker said: “It is perhaps very British to celebrate revolutions by presenting an address to her Majesty."
He added: "But those revolutions led to our constitutional freedoms, set out the foundation for a stable monarchy which protects liberty."
The Lord Speaker, Lord McFall of Alcluith, said of the Queen’s death: “We all now feel a sense of loss beyond measure.” He added: “We remember her commitment, her kindness, her humour, her courage and her fortitude, as well as her deep faith which was the anchor in her life.”
The speeches took place in the most ancient part of Parliament, Westminster Hall, where the Queen will lie in state from 5pm on Wednesday.
Hundreds of MPs and peers sat inside Westminster Hall for the rare joint session of both Houses of Parliament, while staff lined the nearby Colonnade and members of the public stood on Parliament Square.
Former Labour leader Jeremy Corbyn, who skipped Saturday’s meeting of the Privy Council - the only ex-chief of a major party to do so - was in Westminster Hall alongside former PMs Boris Johnson and Theresa May.
It comes 10 years after the last address to both Houses of Parliament to take place in Westminster Hall. Aung San Suu Kyi, the then-Burmese Opposition Leader, made a June 2012 address in the 13th-Century banqueting hall, where the Queen will lay in state.
Extra lights were installed along the stone edges of the ancient hall and the Band of the Household Cavalry played introductory music.
Two red thrones were placed towards the bottom of the steps leading up to Central Lobby, which divides the Commons from the Lords, for Charles and Queen Consort Camilla.
The crowds in Parliament Square cheered as the King's four-car convoy arrived with police outriders. He stepped out of the car first, followed by Queen Consort Camilla, and paused by the North Door of Westminster Hall before they both entered side by side.
Facing the band at the far end of the hall - where Charles I was tried and convicted at the end of the Civil War - was the 2012 Diamond Jubilee window, created following donations from members of both Houses a decade ago.
The King heard messages of condolence from Commons Speaker Sir Lindsay Hoyle and Lords Speaker Lord John McFall before responding.
It comes as the government warned mourners could have to queue for 30 hours to see the Queen lying in state in Westminster.
Culture Secretary Michelle Donelan today warned Tory MPs of the huge number of mourners expected to descend on London for the four-and-a-half day vigil.
She told them in a WhatsApp group: “Queues could be up to 30 hours as we are obviously expecting and planning for unprecedented demand."
An exact "opening time" for the queue has not been released and it was still being set up on Monday morning, with officials preparing to lay out portable toilets and refreshment stands along the route.
Sources told The Times they are expecting 750,000 mourners, outstripping the 200,000 who saw the Queen Mother in 2002, in a five-mile queue.
But it could be more and “there’s just no way of knowing”, one source told the newspaper.
The government is said to be braced for London to become “full” for the first time, with 1,500 soldiers to help stewards man the queue, and 10,000 police officers.
The start of the queue line had already been set up by 7am today.
Private security guards in fluorescent vests were stationed at regular points along the empty line, which had yellow arches and crowd control barriers.
It stretched from Parliament’s tourist entrance Cromwell Green down Millbank, past the Lords and Victoria Tower Gardens, across Lambeth Bridge and looped back north on the other side of the river, towards St Thomas' Hospital.
No one was yet in the queue at 7am, and government officials are asking people not to join the queue for the lying-in-state yet.
Instead, they should only do so after full details of the route have been released at 10pm on Tuesday.
The queue will be open 24 hours a day from 5pm Wednesday to 6.30am Monday.
Mourners are warned they will not be able to take large bags, food and drink or tributes into the Palace, and the queue is "expected to be very long.
“You will need to stand for many hours, possibly overnight, with very little opportunity to sit down as the queue will be continuously moving."
The Queen began her final journey from Balmoral in the Scottish Highlands yesterday, with crowds of people lining the roads as her coffin was borne on the 180-mile trip south to Edinburgh.
Her coffin was placed to rest in the Palace of Holyroodhouse overnight. Today the Queen's coffin will travel in a procession to St Giles’ Cathedral along the Royal Mile with King Charles and the late Queen’s other children Anne, Andrew and Edward following behind on foot.
The late monarch will lie in state for 24 hours in Edinburgh from 5pm today. Her coffin will then be taken to London on Tuesday on an RAF plane.
The solemn procession will then travel to Buckingham Palace by road, where she will rest in the Bow Room.
On Wednesday afternoon, her coffin will be taken on a gun carriage of The King’s Troop Royal Horse Artillery from Buckingham Palace to the Palace of Westminster.
A woman was arrested yesterday after a protester held an anti-monarchy sign ahead of the accession proclamation of King Charles III in Edinburgh.
Graham Smith of campaign group Republic said today: “We all understand that people will want to mourn the death of the Queen.
“Yet at the same time Charles has taken the job of head of state without debate or consent. That's a political act which millions of people object to."
"We don't expect republican voices to be heard in coverage of the Queen's death, but coverage of Charles's accession is a very different matter."
"We are also deeply concerned to see people being arrested for peaceful protest.”
