Prince Charles and Camilla Parker-Bowles have been married for 12 years, but the couple have a long and complicated history. 

Although the couple met when they were young, they both married other people - Camilla married Andrew Parker-Bowles, a retired military officer, but the pair divorced in 2005. Charles famously married Princess Diana, the mother of Prince William and Prince Harry.

Is it possible that Camilla could become Britain’s next Queen? Some believe the Prince intends to make his wife queen, although it was originally planned hat she would be named Princess Consort if Charles took the throne.

However, a shocking Express poll found that 67 per cent of Britons would not accept Camilla as Queen.

Charles, 69, finally married Camilla, 70, in 2005, in a low key ceremony at Windsor Guildhall and Camilla was given an engagement ring that once belonged to his grandmother, Queen Elizabeth The Queen Mother. The Queen and Prince Philip, and Camilla’s parents, did not attend the wedding, supposedly because the couple had both previously been married.

According to one body language expert, their pair’s non-verbal language is incredibly interesting - and although the Prince might be assumed to have the dominant status, Camilla takes charge here.

Body language expert Judi James told Express.co.uk that Camilla has been remarkably strong during the times after Princess Diana’s death and during the negative press in the run up to her marriage to Charles.

Judi said: “Looking back on Charles and Camilla's miss-matching body language from over 30 years ago I would have expected the prince's rather dour, formal and actually quite elderly demeanour to have rubbed off on Camilla over the years, particularly by the time they married and beyond. 

“If the 'Charles Effect' hadn't made Camilla look less cheery and spontaneous then the very negative public opinions following Diana's death could easily have led to her adopting a similar long-suffering expression as the man she loved.

“Remarkably and almost miraculously though these photos prove how Camilla's resilience in terms of body language and her complete lack of desire to change have resulted in creating massive sea-change in Charles's own displays. It's Camilla's sense of fun that has proved influential and contagious while Charles seems to have caught her ability to relax and grin whenever possible.”

In recent public appearance with Camilla, Charles seems far more relaxed than he has in previous times - often smiling, laughing and joking with his wife.

How has their body language changed? In older images of the pair, before Charles married Princess Diana, the royal appears much more serious.

At the polo in 1979 Judi claimed Charles looked: “dour and troubled”.

She said: “Frowning at the ground with his hands stuffed into his pockets in a gesture that usually signals a desire to hide. Camilla is his polar opposite, walking with her head up and the brink of a smile on her face.”

Another image of the pair standing by a car, however, might show a hint of attraction between the couple.

Judi said: “There are signs of attraction to Camilla here in the way his thumb is hooked nonchalantly into his pocket and his right foot is splayed towards her.”

More pictures of the younger couple sitting in a car show even more clearly the differences between the pair.

Charles appeared anxious and serious, and Judi said: “Charles has adopted a signature formal and rather elderly-looking hand clasp and although he's wearing the faintest of smiles on his lips his eye-gaze looks reflective and miserable.”

She adds that the prince also: “Checks his watch in a gesture that became one of his self-checking anxiety ritual gestures.”

Camilla on the other hand seems very relaxed and calm. 

“Camilla's style here is disheveled and spontaneous as though she finds all the press attention enormous fun. Her grin is wide and her head tilt with her hand running through her hair is identical to the pose she uses now, some thirty years later,” Judi said.

Many aspects of the relationship are still very visible today, but Charles and somewhat lightened up - perhaps due to Camilla, who has not lost her youthful habits.

Judi said: “Camilla's body language is identical to when she was first dating Charles and this resilience and lack of change must be hugely attractive to a man who lives in what might be a very chaotic world. 

“She has the same wide grin, head-tilt and hair-raking gesture as she sports in their photos years before and the effect on Charles has been dramatic.

“He is now mirroring his wife with a mirrored wide grin that covers his entire face.

“Charles is the one who has changed dramatically to mirror his wife.”