The Queen's coffin is lying in state at Westminster Hall after a sombre 38-minute procession from Buckingham Palace, with the military playing a vital role in the proceedings.
More than 320 personnel from all services took part in the procession, including more than 170 personnel from The Household Division that guard the Sovereign and Royal Palaces.
Crowds lined the route along The Mall, through Horse Guards Parade and across to Westminster Hall as the procession marched at a pace of 75 steps per minute – a pace specifically reserved for funerals.
Ahead of the procession, detachments of The Life Guards and The Blues and Royals of the Household Cavalry Mounted Regiment formed on the forecourt of Buckingham Palace either side of the centre arch.
The Life Guards stood on the north side, with The Blues and Royals on the south.
On the paved area outside the forecourt in Queen's Gardens was a guard of honour made up of three officers and 101 soldiers from 1st Battalion Coldstream Guards.
Major General Commanding the Household Division, Major General Chris Ghika, who is leading in the ceremonial aspects of the funeral, and his staff took up their positions in front of the gun carriage used to carry Her Majesty's coffin once it was in position in Buckingham Palace's quadrangle.
Watch: Queen's coffin procession: King's Troop Royal Horse Artillery fires 38 gun salutes.
A bearer party from The Queen's Company 1st Battalion Grenadier Guards carried the coffin from within Buckingham Palace to the gun carriage of the King's Troop Royal Horse Artillery known as the George Gun Carriage.
It also carried King George VI's coffin from Sandringham Church to Wolferton Station in 1952 and was used in the funeral of the Queen Mother in 2002.
King Charles III and other members of the Royal Family, including the Prince of Wales, who both wore military uniform for the procession, took up their positions behind the coffin.
The procession left the palace at 14:22, with 1st Battalion Coldstream Guards giving the Royal salute.
Minute guns were fired from Hyde Park by the King's Troop Royal Horse Artillery – one round every minute for the duration of the 38-minute procession.
The King's Life Guard gave the Royal salute as the coffin passed.
A dismounted detachment of more than 50 soldiers of the Life Guards led the procession, with the Household Cavalry and the Household of the Queen, also walking in front of the coffin.
A Blues and Royals marching detachment from the Household Cavalry Mounted Regiment was at the rear of the procession.
Flanking the coffin were pall bearers, the escort party and the bearer party.
The pall bearers were 10 former and serving Armed Forces equerries to Elizabeth II, who were at her side in uniform throughout her reign, supporting her at engagements and organising her public diary.
At 14:30, a guard of honour of three officers and 53 ranks from each service was mounted on Parliament Square - accompanied by the Band of the Royal Marines with drums draped and muffled.
The band provided music as the tri-service guard of honour marched to Parliament Square but stopped once they reached the 100 yards silence zone around the Palace of Westminster.
The Queen's coffin entered Westminster Hall as the choir of Westminster Abbey and the choir of His Majesty's Chapel Royal, St James's Palace, sang Psalm 139.
The King and the senior Royals saluted the coffin as it was carried by a bearer party – eight soldiers from Queen's Company 1st Battalion Grenadier Guards – into the hall.
After a short service, the captain of The Queen's Company 1st Battalion Grenadier Guards, assisted by a senior sergeant, laid The Queen's Company Colour, the Royal standard of the regiment, on the steps of the catafalque at the south end.