A ceremonial procession will transport the coffin down the Mall to Westminster Hall, with a number of Royal Family members set to walk behind the Queen’s coffin.
Thousands of mourners are already lining the streets of central London to pay their respects to the late queen.
As well as the Queen’s children and grandchildren, some lesser-known royals will also be present – including the Duke of Gloucester.
Who is the Duke of Gloucester?
Prince Richard, the Duke of Gloucester, is the late Queen’s first cousin and a full-time working member of the Royal Family.
His parents were Prince Henry, Duke of Gloucester (King George VI’s brother), and Princess Alice, Duchess of Gloucester.
This means that King George VI, (Queen Elizabeth’s II’s father), was his uncle.
He was born on August 26, 1944, and was christened Richard Alexander Walter George.
The Duke of Gloucester studied at Eton and Cambridge and began working as an architect, before his elder brother’s death meant that he became his father’s heir and had to take on additional royal duties.
He married his wife, Birgitte van Deurs, in 1972, and they have three children together: the Earl of Ulster (born 1974), the Lady Davina Windsor (now the Lady Davina Lewis, born 1977) and the Lady Rose Windsor (now the Lady Rose Gilman, born 1980).
The official Royal Family website states: “The Duke is associated with over 150 charities and organisations.
“His patronages reflect his professional and personal interests, which include international humanitarian issues, heritage and the built environment and military veterans.”