Mourners packing the streets of central London on Monday for Queen Elizabeth II's funeral watched in awe as the coffin of the only monarch most Britons have ever known made its final journey.

A sea of arms held up mobile phones in Parliament Square to film the spectacular procession bearing the queen's casket from Westminster Abbey after a service attended by leaders from around the world.

Retired nurse Maryann Douglas, 77, who moved from New York to London four years ago, struggled to find the words to express her feelings after waiting for hours to pay her respects.

"I knew it would be good but it was better than I expected, I had tears in my eyes and chills," she said.

"It's an emotion you can't really describe when you see the queen's coffin go by."

A total silence fell over the thousands who had gathered in Hyde Park as they watched the funeral service being broadcast on big screens.

Rhiannon Turnbull, 31, and her partner Julie Taylor had driven four hours from south Wales to be at the heart of events.

"I feel overwhelmed," said Turnbull.

"We can be very proud of being all together here in this park. There are people of every age, children, adults."

- Camped out -

As dawn broke over the River Thames, thousands of well-wishers were already streaming out of the underground rail stations to join those who had camped out overnight in the Whitehall government district.

"It's part of history," said Bethany Beardmore, 26, an accountant whose brother is a Grenadier Guard and part of the ceremonies.

"Not in my lifetime is there going to be another queen."

Beardmore arrived at 9:00 pm (2000 GMT) on Sunday but, fuelled by too much sugar and caffeine, found it impossible to sleep in the cold.

"Everyone was chatting," she said.

Retired health care worker Veronica Knibbs-Hughes, who is black, said she believed the sense of unity over recent days, culminating in the funeral, "will ricochet in some good way.

"Each and everyone of us will take away something. I am from an ethnic minority, I feel a bit marginalised sometimes and now it's very inclusive.

"This is the people speaking, we are a silent voice, but we are speaking," the 69-year-old added.

The mood on Whitehall was upbeat in the build up to the funeral, but at 10:44 am, the mood turned sombre, with the sound of pipes drifting across the crowd signalling that the queen's body was being moved to Westminster Abbey.

Crowds huddled around those who managed to find a live-stream on their phones, echoing the queen's 1953 coronation, when families gathered at households lucky enough to have a television set.

Others had to make do with a radio broadcast of the service played over the loudspeakers.

The queen's flag-draped coffin had lain in state at parliament's Westminster Hall from Wednesday.

Hundreds of thousands are estimated to have filed past to pay their respects.

The doors to the hall were finally shut at 6:30 am on Monday to prepare for the coffin's transfer to Westminster Abbey.

The last member of the public to pass through the hall was Chrissy Heerey, a serving member of the Royal Air Force.

"It feels amazing," she told AFP. "When they came to me and said, 'Right, you're the last person', I said, really?"

- 'A pilgrimage' -

In Windsor, six giant screens showing the funeral were set up along the sweeping Long Walk to the queen's final resting place in the castle.

Elizabeth Turner, 60, had come all the way from British Columbia in Canada, which also counted the queen as head of state, and was waiting with her niece among the families sharing food and chatting.

"It is like a pilgrimage to be at Windsor. It's poignant to see all these people who have come to pay homage," she said.

"It is a symbolic place because when the queen enters Windsor Castle it will be the last time to see her. We wanted to witness that."

Marianne Smith, 39, struggled to contain her emotions after leaving home early with her family to be among the crowd.

"We watched with all these people from the Queen's home, Windsor, and it was lovely, so emotional, just beautiful," she said. "All the crowd lived the moment."