At its core, the appointment of the Duchess of Cornwall as a member of the Order of the Garter represents a unifying gesture.

It is at the beginning what will be Queen’s Platinum Jubilee years, which binds together the Inner Circle of Royal Family members after 12 months filled with controversy, turbulence and profound personal losses.

It also opens the door for the Duchess of Cambridge to be Queen in her own right, when Prince Charles is succeeded to the throne.

This is what we can be sure of. And with this latest announcement, there is no greater honour – or better indication of the respect in which she is held by the Queen.

The appointment of the Duchess of Cornwall to the prestigious Order of the Garter is, at its heart, a unifying gesture, writes HUGO VICKERS

HUGO VICTORY writes: Hugo VICKERS believes that the appointment of the Dukes of Cornwall into the Order of the Garter, is a very unifying gesture.

The Duchess also has an additional position, should her husband pass away. It is clear that Camilla plays a central role in the British monarchy’s future.

The gesture is the latest in a long line of advancements for the Duchess, who – it is fascinating to observe – changed from hated mistress to supportive wife more or less overnight when she married Charles in April 2005.

She felt like an entirely new person after becoming an HRH. Her acceptance was actually gradual. 

Charles could have his wife adorned with family jewels. Margaret Greville was soon seen sporting Margaret Greville’s stunning tiara (and five-strand necklace) that the society hostess turned philanthropist left to her Queen Mother.

Further evidence of the family’s admiration came when Camilla was given the Royal Family Order in 2007 – an image of the Queen worn on a pale-yellow moiré ribbon – which is bestowed on most HRHs except, notably, the Duchess of York and Princess Michael. 

In 2012, she was awarded the Grand Cross Royal Victorian Order. This award is usually presented to Royal Ladies.

Her appointment in 2016 to the Privy Council was a first. It includes Cabinet Ministers as well as the Queen’s private secretary. 

Charles was elected in 1977, and Duke of Cambridge was in 2016.

It’s worth noting that Queen Mary and the Queen Mother – the last two wives to Kings – were never Privy Counsellors.

It is the Order of the Garter founded in 1348 that is Camilla’s most significant achievement. 

It comes at the beginning of what will be the Queen's Platinum Jubilee year, binding together the inner circle of the Royal Family after 12 months of turbulence, controversy and deep personal loss. Pictured: Camilla with the Queen and Prince Charles at the G7 summit in June

It marks the beginning of the Queen’s Platinum Jubilee years, which will bring together the royal Family’s inner circle following 12 months of turmoil and controversy. Pictured: Camilla and Prince Charles with Queen Elizabeth II at June’s G7 Summit

Over its long history, it has included many members like the Black Prince and the great Dukes Marlborough and Wellington as well as Benjamin Disraeli, Sir Winston Churchill, and Benjamin Disraeli.

Membership to its inner circle is strictly limited: the Sovereign and the Prince of Wales are automatically members, along with no more than 24 Knight Companions – appointments made at the sole discretion of the Sovereign, and usually in recognition of a notable contribution to society.

Although women are long associated with Garter since ancient times, until 1987 they were not allowed to be full Lady Companions. 

They include Lady Mary Fagan (former MI5 chief), Lady Mary Peters, Baroness Amos, and Lady Mary Peters. However, Princess Anne was appointed in 1994 and insisted that the Queen made her a Knight in the Garter instead of a Lady to be equal with her brothers.

There are supernumerary Order members as well, who don’t count towards the upper limit. 

To allow King George III to appoint nine of his sons, he introduced this group. And it is into this group – known as the Royal Knights and Ladies – to which Camilla has been appointed. It is her first marriage to an heir of the throne, and certainly the first in 120 years.

Garter Day is the normal Monday during the Royal Ascot week. 

The solemn ceremony is attended by the members in their historic dark-blue velvet mantles, Tudor bonnets, and Tudor garters. It takes place at Windsor Castle’s magnificent Garter throne.

But, more than that, it paves the way for the Duchess to become not only Queen by right when Prince Charles succeeds to the throne, but Queen by name. Pictured: Camilla with Prince Charles, the Queen, Prince Philip, Prince William and the Duchess of Cambridge in 2016

More than this, the duchess will be able to succeed Prince Charles to the throne by becoming Queen by right. Pictured: Camilla and Prince Charles with Prince Philip, Prince William, Prince William, and Prince Charles in 2016.

Camilla will have the option to wear the Garter blue riband across her left shoulder, star and even the Garter herself on her right arm. 

After lunch at the Waterloo Chamber there is a spectacular procession that includes Military Knights of Arms, Officers of Arms, as well as members of the Order of St George’s Chapel.

She will announce her approval that Camilla should be installed. Then, she will be taken to the Chapel wall’s carved wooden stalls. 

Her banner will be hung above the stall, while her coronet is located on the top. There will be much more discussion about the choice of stall.

Camilla should be placed next to Prince of Wales, as it is the most suitable and likely location. 

This would mean moving the Duke of York – who currently occupies that stall – elsewhere.

It isn’t necessarily important. In reality they do move the Royal banners around if need be – as happened with the Queen Mother, whose banner was moved three times. 

However, Prince Philip’s stall has been empty since his death and will likely remain vacant for the remainder of Queen Elizabeth’s reign.