The king and other senior royals were seen walking in silence behind the hearse.
King Charles led a procession of the coffin of his mother Queen Elizabeth II through London on Wednesday before hundreds of thousands of people pay their final respects.
Queen Elizabeth's body was borne on a horse-drawn gun carriage from her Buckingham Palace home to Westminster Hall where she will remain for four days until her funeral next Monday.
The king and other senior royals were seen walking in silence behind the hearse as it winds through the capital's streets and then hold a vigil upon its arrival at the cavernous 12th-century hall in the Westminster parliament complex.
Strict rules and airport-style security measures have been put in place, with "far more" people expected than the 200,000 who filed past the coffin of the queen's mother when she died in 2002, according to Prime Minister Liz Truss's spokesman.
Here are the Highlights on Queen Elizabeth's Funeral Procession
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Queen's coffin reached Westminster Hall where it will lie in state
Queen's coffin reached Westminster Hall where it will lie in state
Queen Elizabeth II: Flight carrying coffin to London most tracked plane in history Nearly six million people tried to follow a British Royal Air Force transport aircraft taking Queen Elizabeth II's coffin from Edinburgh in Scotland to London, making it the most tracked flight in history, website Flightradar24 said on Wednesday.
The Queen's coffin was flown on a RAF Globemaster C-17 on Tuesday evening, after lying in state at St Giles' Cathedral in Edinburgh.
The previous record was when a US military aircraft carrying US House Speaker Nancy Pelosi to Taiwan last month was followed by 2.2 million people on Flightradar24.
On Tuesday, nearly six million people tried to follow the British military plane's route from Edinburgh to RAF Northolt within its first minute in the air, the website said.
Queen's coffin heads to Westminster Hall
Senior royals are part of procession.
Horses trained to hear ‘sobbing’ during London Queen’s processionHorses participating in the procession of late Queen Elizabeth's coffin from Buckingham palace to Westminster Hall have undergone special training. 'Crying' soldiers threw flowers at the horses several times during the rehearsal to make them familiar to the sound of 'sobbing'.
Thousands of Britons have made their way to London to pay their respects to the Queen, one last time. King Charles III will lead the procession behind the Queen's coffin which will be carried by a horse pulled gun carriage.
Prince William and his brother Harry will walk behind their father King Charles III, like they did under unfortunate circumstances 25 years ago, behind their mother, Princess Diana's coffin. An outpour of grief is expected, as people turn up with flowers, flags and pictures of the late Queen.
Queen Elizabeth's Funeral: These Are The People Expected To Be In AttendanceThe Queen's funeral will be held at Westminster Abbey with over 2,000 guests from all across the world and 500 royals, heads of state and other dignitaries are expected to attend. It is set to be one of the biggest international events hosted by the UK in decades.
A BBC report says that the majority of leaders have been asked to arrive on "commercial flights and told they will be bussed en masse from a site in west London".
The funeral will take place on September 19 at 3.30 pm (India time).
The procession routeThe procession will go through the Mall, Horse Guards and Whitehall, Parliament Street, Parliament Square and New Palace Yard.
After a short service, the Queen's lying in state will begin, lasting for four days and ending on the morning of the state funeral. (September 19).
Queen’s coffin procession
The ceremony will see the coffin on a gun carriage from Buckingham Palace to Westminster Hall for lying in state.
The King will lead a procession behind the late Queen's coffin.
The coffin will leave Buckingham Palace at 6.55 pm (IST) and arrive at Westminster Hall at 8 pm (IST)
President Murmu to attend State Funeral of QueenPresident Droupadi Murmu will visit London, UK from September 17-19 to attend the State Funeral of Queen Elizabeth II and offer condolences on behalf of the Indian government.
"Queen Elizabeth II, the former head of state of the UK and Head of the Commonwealth of Nations passed away on 8 September. President Droupadi Murmu, Vice President Jagdeep Dhankhar and Prime Minister Narendra Modi have expressed condolences at the demise of Queen Elizabeth II. External Affairs Minister Dr S Jaishankar visited the British High Commission in New Delhi on 12 September to convey India's condolences. India also observed a day of national mourning on Sunday, 11 September," read the Ministry of External Affairs statement.
The statement added in the 70 years of the reign of Queen Elizabeth II, India-UK ties have evolved, flourished and strengthened immensely. She played an important role in the welfare of millions of people worldwide as Head of the Commonwealth.
"Fortunate To Share Last 24 Hours...": Princess Anne's Note For Queen
Anne, The Princess Royal, only daughter of the longest serving monarch of the UK Queen Elizabeth II, and Prince Philip, wrote a heartfelt note for her mother, as she accompanied her coffin back to Buckingham Palace.
Grieving the loss of her mother, the Queen's second child, The Princess Royal wrote that she was fortunate to share the last 24 hours of her dearest mother's life, as the coffin of the Queen travels from Balmoral to London for the final rites.
Read MoreWith Over 5 Million Views, Queen's Final Flight Is Most Tracked Ever
Over 5 million people viewed Queen Elizabeth's final flight on Tuesday, as the journey carrying the late monarch's body from Edinburgh to London became the most tracked flight in history.
Flight tracking website Flightradar24 said a total of 4.79 million people watched the flight live online, with a further quarter of million people watching on its YouTube channel.
Read More