King Charles will break with a long-standing tradition at his coronation next month to pay a fitting tribute to his mother, the late Queen.
Ceremonial celebrations for the historic event have been unveiled, detailing Charles and Camilla's procession route, as well as their decision to only use the 260-year-old Gold State Coach one way - on their return.
The pair will make the 1.3 mile outward journey - known as the King's Procession - from Buckingham Palace in the Diamond Jubilee State Coach, which was made to commemorate Elizabeth II's 80th birthday.
The air-conditioned coach is more comfortable and modern than the Gold State Coach, which was built in 1762 and has been used at every coronation from William IV onwards.
The late Queen rode both ways in the Gold State Coach for her 1953 coronation, famously describing the bumpy experience in the carriage, which is suspended on leather straps, as "horrible".
On May 6, Charles and Camilla will travel down The Mall via Admiralty Arch, along the south side of Trafalgar Square.
They will continue along Whitehall and Parliament Street, around the east and south sides of Parliament Square to Broad Sanctuary to arrive at the Abbey.
A Buckingham Palace spokesperson said: "The carriages chosen reflect the smaller procession to the Abbey and the larger procession back to Buckingham Palace.
"They were the personal choice of Their Majesties."
The Palace declined to comment on whether the decision to opt for the Diamond Jubilee State Coach at the start has anything to do with ongoing back pain the King has suffered for many decades. Camilla has also endured back problems over the years.
The black and gold Diamond Jubilee carriage, built in Australia and first used by the late Queen at the State Opening of Parliament in 2014, is the newest in the Royal Mews.
It features modern technology, with six hydraulic stabilisers to stop it from swaying, and traditional craftmanship with interior wooden panels made from objects donated by more than 100 historic sites.
Charles' Coronation Procession in the Gold State Coach will feature a cast of hundreds of members of the Armed Forces from the UK, Commonwealth and the British Overseas Territories, as well as the Sovereign's Bodyguard and Royal Watermen.
It will take longer than his outward journey because the historic gilded carriage, which will be drawn by eight Windsor greys, is so heavy it has to travel at walking pace.
Sally Goodsir, curator of decorative arts at the Royal Collection Trust, said: "The Gold State Coach will be the centrepiece of the much larger procession from Westminster Abbey back to Buckingham Palace on coronation day.
"It weighs four tonnes and because of that it can only be used at walking pace which really adds to the majesty and stateliness of this great royal procession."
The priceless array of coronation regalia from the Crown Jewels which will be used during the religious service in the Abbey has also been confirmed.
It will include the Sovereign's Orb, the Golden Spurs, bracelets known as Armills, two maces, five symbolic swords, the Sovereign's Ring, the Sovereign's Sceptre with Cross and the Sovereign's Sceptre with Dove.
Camilla will be crowned, as previously announced, with the modified Queen Mary's Crown, but she will also hold the Queen Consort's Rod with Dove - despite the controversial rod being made from ivory.
The piece is said to symbolise equity and mercy, and the dove, with its folded wings, represents the Holy Ghost.
Camilla will also hold the Queen Consort's Sceptre with Cross, which originally made for the coronation of Mary of Modena, Queen Consort of James II, in 1685 and is inlaid with rock crystals.
As part of the proceedings, she will receive the Queen Consort's Ring - a ruby in a gold setting made for the Coronation of King William IV and Queen Adelaide in 1831, and used by three further Queens Consort - Queen Alexandra, Queen Mary, and the Queen Mother.
As previously announced, Charles will be crowned with the 17th century St Edward's Crown which has been resized to fit his head.
He will switch it for the lighter Imperial State Crown at the end of the ceremony as is the custom.
Other details announced by the Palace include a new Twitter emoji.
The motif of St Edward's Crown has been specially designed to mark the weekend of coronation festivities.
The King and Queen Consort will also receive a royal salute in the Buckingham Palace gardens from the military troops on parade.
They will take the salute from the West Terrace after the ceremony and the servicemen and women will give three cheers - a special coronation tribute from the Armed Forces to the couple.
