The UK has now entered a period of national mourning following the death of Her Majesty The Queen on September 8, 2022.
According to a statement from Buckingham Palace, the Queen died peacefully at Balmoral Castle in Scotland.
Intricate plans had been drawn up for when Her Majesty sadly passes away, codenamed Operation London Bridge or Operation Unicorn in Scotland, that details what will happen following the monarchs death, including funeral plans.
The Queen's coffin was brought down to London from Edinburgh on September 13
According to the detailed Operation London Bridge plan, she will be transported from Buckingham Palace to Westminster Hall in the capital, where her coffin will lie in state for four days, starting on today (September 14).
But what does Lying-In-State mean and what is the significance of her body going to Westminster Hall?
What does Lying-in-State mean?
The tradition of Lying-in-State is where the body of a deceased official is placed in a state building either inside or outside of a coffin so the public can come to pay their respects.
In the UK, Lying-in-State historically takes place at Westminster Hall in London.
The body is flanked by guards, however, only on two occasions has an official's deceased body been mounted by members of the Royal Family.
Following the Queen Mother's death in 2002, the guard was mounted by her four grandsons - the former Prince of Wales, the Duke of York, the Earl of Wessex, and Viscount Linley.
So far, the vigil has only been carried out by male members of the Royal Family but this could change for the Queen's vigil at Westminster Hall as her daughter, Princess Anne, could guard the coffin.
What is the significance of the Queen's body lying in Westminster Hall?
The role of Lying-in-State is usually only reserved for the sovereign, current or past Queen Consorts, and occasionally other distinguished figures, such as former prime ministers.
Queen Elizabeth II's body will be the first to lie in state for the last 20 years, after the Queen Mother in 2002 where over 200,000 people came to pay their respects.
The practice may date back to the 17th century but the first monarch to lie in state was King Edward VII in 1910.
As the Queen passed away in Scotland, under Operation Unicorn, the plan for if the Queen dies in Scotland, she had a smaller ceremony at St Giles' Cathedral in Edinburgh which took place on September 12.
When will the Queen be Lying-in-State at Westminster Hall?
The Queen's coffin made the journey from Edinburgh to London on September 13 and she will begin Lying-in-State today (September 14) for four days ahead of her funeral on Monday, September 19.
Her coffin will be taken to Westminster Hall where it will be placed on a raised platform - known as a catafalque - in the middle of the room.
The coffin will then be draped in the Royal Standard flag with the Imperial State Crown, orb and sceptre resting above it.
In order to see the Queen Lying-in-State, the public will simply have to turn up on the day they wish to visit to pay their respects and the hall will be open 24 hours a day from 5pm on September 14 until 6.30am on September 19.
