LONDON (AP) — Thousands of mourners waited hours in line for the chance to spend a few minutes filing past the coffin of Queen Elizabeth II while it lay in state at Britain’s Parliament on Thursday, as King Charles III spent the day in private to reflect on his first week on the throne.

The queue to pay respects to the late queen at Westminster Hall stretched by Thursday afternoon to 4.4 miles (seven kilometres) — a nine-hour wait. The line snaked across a bridge and along the south bank of the River Thames beyond Tower Bridge.

People said they didn’t mind the wait.

“I’m glad there was a queue because that gave us time to see what was ahead of us, prepared us and absorbed the whole atmosphere,” health care professional Nimisha Maroo said. “I wouldn’t have liked it if I’d had to just rush through.”

A week after the queen died at her Balmoral Estate in Scotland after 70 years on the throne, the focus of commemorations was in Westminster — the heart of political power in London. Her coffin will lie in state at Westminster Hall until Monday, when it will be taken across the street to Westminster Abbey for the queen’s funeral.

Buckingham Palace released details of the service, the first state funeral to be held in Britain since the death of former Prime Minister Winston Churchill in 1965. Royalty and heads of state from a round the world are expected to be among the 2,000 people attending, with a smaller burial service planned for later Monday at Windsor Castle.

At the end of the day, the queen will be buried in a private family service at Windsor alongside her late husband, Prince Philip, who died last year.

After a day of high ceremony and high emotion on Wednesday as the queen was carried in somber procession from Buckingham Palace, the king was spending the day working and in “private reflection” at his Highgrove residence in western England. Charles has had calls with U.S. President Joe Biden and French President Emmanuel Macron and is speaking to a host of world leaders — many of whom will come to London on Monday for the queen’s funeral.

Heir to the throne Prince William and his wife Kate visited the royal family’s Sandringham estate in eastern England to see some of the tributes left by well-wishers. The couple walked slowly along metal barriers as they received bouquets from the public and chatted to well-wishers. Other royals fanned out across the U.K. to thank people for their support, with the queen’s son, Prince Edward, and his wife Sophie visiting Manchester and his sister Princess Anne in Glasgow.

On Wednesday the queen left Buckingham Palace for the last time, borne on a horse-drawn carriage and saluted by cannons and the tolling of Big Ben, in a solemn procession through the flag-draped, crowd-lined streets of London to Westminster Hall.

Charles, his siblings and sons marched behind the coffin, which was topped by a wreath of white roses and the queen’s diamond-studded crown on a purple velvet pillow.

The military procession underscored Elizabeth’s seven decades as head of state. Her lying-in-state allowed many Britons to say a personal goodbye to the only monarch most have ever known.

It’s also a huge logistical operation, with a designated 10-mile (16 kilometres) queuing route lined with first aid points and more than 500 portable toilets. There are 1,000 stewards and marshals working at any given time, and 30 religious leaders from a range of faiths to stop and talk to those in line.

Monica Thorpe said she walked for two hours to get to the back of the line and join the queue.

“People were just walking and walking and the policemen were like ‘Keep going, keep going.’ It was like the yellow brick road,” she said.

Archbishop of Canterbury Justin Welby, the spiritual leader of the Church of England, wore a high-visibility vest emblazoned with the words “Faith Team” as he spoke to mourners.

Welby, who will deliver a sermon at Elizabeth’s funeral on Monday, paid tribute to the queen as “someone you could trust totally, completely and absolutely, whose wisdom was remarkable.”

Thousands have already paid their respects, filing past the casket draped with the royal standard and topped with a diamond-encrusted crown.

People old and young, dressed in dark suits or jeans and sneakers, walked in a steady stream through the historic hall, where Guy Fawkes and Charles I were tried, where kings and queens hosted magnificent medieval banquets, and where previous monarchs have lain in state.

After passing the coffin, most mourners paused to look back before going out through the hall’s great oak doors. Some were in tears; others bowed their heads or curtseyed. One sank onto a knee and blew a farewell kiss.

Keith Smart, an engineer and British Army veteran, wiped away tears as he left the hall. He had waited more than 10 hours for the chance to say his goodbye.

“Everybody in the crowd was impeccably behaved. There was no malice, everybody was friends. It was fantastic,” he said. “And then, to come into that room and see that, I just broke down inside. I didn’t bow — I knelt to the floor, on my knees, bowed my head to the queen.”

The late-night silence was broken when one of the guards standing vigil around the coffin collapsed and fell forward off a raised platform. The man, his chest adorned with medals, could be seen on livestreams of the queen’s coffin lying in state swaying on his feet before pitching forward onto the floor. Two police officers rushed to his assistance.

Crowds have lined the route of the queen’s coffin whenever it has been moved in its long journey from Scotland — where the monarch died Sept 8, aged 96 — to London.

On Tuesday night, thousands braved a typical London drizzle as the hearse, with interior lights illuminating the casket, drove slowly from an air base to Buckingham Palace.

Earlier, in Edinburgh, about 33,000 people filed silently past her coffin in 24 hours at St Giles’ Cathedral.