Queen Elizabeth is lying in state before her funeral. What does that mean?

For the next four days before the funeral in Westminster Abbey on Monday Queen Elizabeth's casket is lying in state in Westminster Hall, as people who have lined up for hours will have a brief moment of reflection as they file silently by the coffin.

While this all unfolds in a Gothic building of deep political and historical significance dating back to 1097, the actual history of lying in state is more recent relatively speaking.

Lying in state is a "modern invention or reinvention," said Judith Rowbotham, a social and cultural scholar and visiting research professor at the University of Plymouth in southwestern England, in an interview.

"What happened in the medieval period to prove that the king was really dead was that the great dignitaries of the kingdom would be invited to view the body of the late monarch lying in state. Then, [the body] just gets forgotten, not observed."

A new tradition emerged around the death of a monarch in the 17th and 18th centuries, Rowbotham said, with a kind of lying in state that occurred in private."It wasn't public. It was for the senior politicians, the senior peers of the realm and the royal household."

It didn't last very long, and monarchs were buried at night, under the cover of darkness, with everything lit by torchlight, Rowbotham said. She noted that the last monarch to have that experience was King William IV, who died in 1837.

Queen Victoria's influence

Things changed, however, by the time it came to the passing in 1901 of William's successor, Queen Victoria.

Victoria, who was great-great grandmother to Elizabeth, had no particular view of her own funeral, Rowbotham said. But during her reign, the groundwork was laid for the kind of lying in state happening now.

Victoria and her husband, Prince Albert, wanted the Duke of Wellington, the soldier and statesman who died in 1852, to have a state funeral, which included a public lying in state.

"It wasn't always orderly, that lying in state, but [Victoria] was very impressed by the military pomp and the show of the funeral itself, the service and things like that," Rowbotham said.

WATCH | Queen Elizabeth's coffin leaves Buckingham Palace to lie in state:

Queen's coffin leaves Buckingham Palace to lie in state

2 years ago

Duration 4:04

Massive crowds converged on London to see the Queen's coffin move in a horse-drawn carriage to the Houses of Parliament to lie in state.

While there was no public lying in state for Victoria before her funeral in 1901, there was a private one for family and members of the Royal household.

But when her son, who became King Edward VII, died in 1910, there was a public lying in state.

"Queen Elizabeth once said, 'I have to be seen to be believed,' and Edward observed that throughout his reign," said Rowbotham.

"I think Edward, who was very good at pageantry, realized that his funeral at the end of a pretty short reign would best leave its mark both nationally and internationally if he instituted a public lying in state, which is what he [did]."

After the deaths of George V in 1936 and George VI in 1952, there were alsosuch events.

"The public every time turns out to pay their respects to these monarchs, so it's become an established tradition," said Rowbotham.

Securing a standing tradition

While it's become tradition, the scale of what will unfold over the next few days and the security required for it could be unprecedented. Some estimates of how many people will file by Elizabeth's coffin are as high as 750,000. One report suggested the linecould be temporarily shut down if it stretches more than 16 kilometres.

"We are expecting enormous queues," said Craig Prescott, a constitutional expert at Bangor University in Wales.

There's talk, he said, "of waiting 30 hours to file past, with the queue stretching basically across London, which is extraordinary, going from Westminster onto the south bank, the other side of the river [Thames] and then along the river past London Bridge, past Tower Bridge. It's a long way to Tower Bridge, but that's really only half way."

The plans, Prescott said, are intended to allow as many people as possible to see the Queen's casket.

"There is always a relationship between the monarch and the people. And essentially, the monarch exists by public consent and it's an opportunity for individuals to perhaps have their own private moment and to say thank you to the Queen for the service that she's given the country and the Commonwealth for the past 70 years."

'Willing to do this'

For all that waiting, it will be a relatively brief moment any individual will have in front of the casket. And yet, so many are lining up for it.

"I think it shows the value in which they hold the Queen [that] they're willing to do this," said Prescott.

"I think it shows that she perhaps in many ways transcended even being a mere monarch and had some sort of deep position in the British national psyche by simply being there for so long."

The lying in state is also expected to include a vigil with the Queen's four children King Charles, Princess Anne, Prince Andrew and Prince Edward standing in silence, each at a corner of her coffin.

It is the latest rendition of the Vigil of the Princes, a tradition Rowbotham calls "very modern," in the sense that it dates only as far back as the death of George V, who had four sons who stood vigil at his coffin in 1936.

"It was a purely private thing, that vigil. There isn't a photograph of it," said Rowbotham. "It was a private and spontaneous decision taken out of grief."

No similar vigil happened for George VI, but it returned after the death of his widow, Queen Elizabeth, the Queen Mother, in 2002. Charles, Andrew, Edward and their cousinDavid, the son of the Queen's sister, Princess Margaret, took their turn as her coffin lay in state in Westminster Hall.

Earlier this week, the vigil unfolded again at St. Giles Cathedral in Edinburgh, with Charles, Anne the first woman to participate in such a vigil Andrew and Edward standing around their mother's coffin for a short time.

"It reflects the private and public nature of all of this," said Prescott.

"It shows the respect that the Royal Family held the monarch in and also shows [the role] the Royal Family, in particular the King, now play in leading the nation in their grief as well."