It has also been used for the funerals of several other monarchs, including those of King Edward VII, King George V and the Queen's father, King George VI, in 1952.
It also featured in the funerals of the Queen's first prime minister, Winston Churchill, and was last used in 1979 for her cousin, Lord Louis Mountbatten.
In keeping with tradition, the gun carriage – which set off from Westminster Hall, where the Queen had been lying in state, at 10:44 a.m. – was being drawn by 142 Royal Naval Ratings, who are service personnel.
The tradition of sailors pulling the coffin was brought in after the horses used to pull Queen Victoria's coffin in 1901 for her funeral were spooked and almost tipped her coffin.
The carriage was being flanked by the bearer party, pallbearers made up of the Queen's service equerries, as well as detachments of the King's Body Guards of the Honourable Corps of Gentlemen at Arms, The Yeomen of the Guard and the Royal Company of Archers.
After the funeral at Westminster Abbey, it will be part of a procession that will stretch about a mile. King Charles III, as well as other members of the Royal Family, will follow behind the carriage.
The Queen Consort, the Princess of Wales, the Countess of Wessex and the Duchess of Sussex will join the procession in cars.
