At first glance they might seem to have little in common.

One is the brusque, no-nonsense sister of the King, famous for her straight talking approach to royal duties.

The other is her softer-edged sister-in-law, popular thanks to her feminine style and sympathetic manner.

But the Princess Royal and the Duchess of Edinburgh share an impressive work ethic - so it was probably inevitable they would find themselves working in tandem at some point.

Princess Anne speaking to war veterans at a reception at Buckingham Palace

Sophie, Duchess of Edinburgh, shakes hands with the Director of Remembrance Philippa Rawlinson

They were even colour co-ordinated when they held a reception on behalf of the King

They have always seemed to enjoy each other's company, seen here at the Westmorland county Show in Cumbria in 2021

Last week they stepped in for the King, who is currently undergoing treatment for cancer, at a Buckingham Palace reception for veterans of the 1950 to 1953 Korean War.

Anne and Sophie have rarely been paired in this way, yet they seemed to have an easy rapport and were an an instant hit with fans on social media.

‘Just love those ladies,' wrote one.

Others commented: ‘I like this partnership, two fantastic women’ and ‘lovely to see such marvellous ladies sharing this event,’ wrote another’.

The Princess, 73, and the Duchess, 59, have been friends for years and have been spotted together at social events from Royal Ascot to the (slightly less high-profile) Westmorland County Show in Cumbria.

But it is rather unusual for them to host a working engagement together.

Palace insiders said there is no plan to make a feature of the pairing, which came about because of the King's condition.

Other royals are stepping up when their diaries are free and their interests align.

Sophie mainly does engagements alone or with her husband, the Duke of Edinburgh, who has this week been away on a visit to Uganda.

So the Duchess was free to join the formidable Princess Anne, who told the 200 or so guests at the Palace that she was ‘so glad Sophie and I have been asked to help out’.

Princess Anne and Sophie speak to Major General Eldon Millar and Yoon Yeocheol, South Korean Ambassador to the UK

Sophie and Anne sit together in the carriage for the Order of the Garter ceremony

Here they are seen leaving the National Service of Thanksgiving as part of the celebrations of the Platinum Jubilee  in 2022

It was no secret that Anne and Sophie were favourites of the late Queen

After all, it’s no secret that both women had been favourites of the late Queen.

In 2015 they both accompanied Her Majesty to the Women’s Institutes centenary meeting - a huge compliment bearing in mind the affection in which Queen Elizabeth held the WI.

Might it be time to see a little more of this dynamic duo?