LONDON (AP) — King Charles III and Camilla, the Queen Consort, are leading the procession into Westminster Hall for a service marking the arrival there of Queen Elizabeth II’s coffin.

Princess Anne and her husband, retired Vice Admiral Timothy Laurence, and Prince Edward and his wife Sophie, the Countess of Wessex, are following behind.

Prince William and his wife Kate, the Princess of Wales, and Prince Harry and his wife Meghan, the Duchess of Sussex, appear next in the royal entourage.

Camilla, Sophie, Kate and Meghan did not take part in Wednesday’s procession through part of London, but they joined their spouses as the group entered Westminster Hall.

The procession comes before a short service of prayer for the monarch, who died last week after 70 years on the throne.

The queen will lie in state at Westminster Hall, part of the Houses of Parliament, until early Monday morning when her funeral is held.

About a half-hour before the procession was due to start, the gun carriage passed through the palace’s wrought iron gates.

London’s Heathrow Airport halted flights that could disturb the procession. British Airways canceled 16 flights as a result of the changes.

The airport said in a statement that the changes would “ensure silence over central London as the ceremonial procession moves from Buckingham Palace to Westminster Hall.”

The crowds are the latest manifestation of a nationwide outpouring of grief and respect for the only monarch most Britons have ever known, who died at her beloved Balmoral summer retreat on Thursday at age 96, ending a 70-year reign.

“It’s a very sad day, but it’s our last opportunity to do our duty for the queen and it’s our first opportunity to do it for the king, and that makes us all very proud,” said Maj. Gen. Christopher Ghika, of the Household division, who is responsible for organizing the ceremonial aspects of the Queen’s funeral.

Sgt. Tom Jenks, from the King’s Troop Royal Horse Artillery, said that the horses have undergone special training for the funeral, including how to handle weeping mourners, as well as flowers and flags being thrown onto streets as the procession passes by.

Earlier, in Edinburgh, some 33,000 people filed in silent respect past her coffin as it lay for 24 hours at St. Giles’ Cathedral.

The hall is where Guy Fawkes and Charles I were tried, where kings and queens hosted magnificent medieval banquets and where ceremonial addresses were presented to Queen Elizabeth II during her silver, golden and diamond jubilees.

Chris Bond, from Truro in southwest England, was among those lining up along the banks of the River Thames. He also attended the lying in state of the queen’s mother in 2002.

“Obviously, it’s quite difficult queuing all day long, but when you walk through those doors into Westminster Hall, that marvelous, historic building, there was a great sense of hush and one was told you take as much time as you like, and it’s just amazing,” he said.

“We know the queen was a good age and she served the country a long time, but we hoped this day would never come,” he added.