Princess Charlotte showed 'calm confidence' and was the 'standout star' of the Royal Family's Buckingham Palace balcony appearance, a body language expert has claimed.

King Charles and Queen Camilla were accompanied by the Prince and Princess of Wales at Trooping the Colour, the monarch's official birthday parade in London, on Saturday, as well as other senior royals such as Princess Anne and Prince Edward.

Joining Kate and William were their three children, Prince George, 12, Princess Charlotte, 11, and Prince Louis, eight, who sat next to their mother in the carriage procession along The Mall before appearing on the balcony. 

While Louis put on an animated display whilst watching the flypast, and George showed off his impressive height, nearly standing as tall as 5ft9in Kate, who was wearing heels, Charlotte was the real 'star', resembling the late Queen Elizabeth II, according to Judi James.

The body language expert told The Daily Mail: 'Charlotte was the solo, standout star of the balcony appearance, projecting a calm confidence and being the one royal standing to attention and gazing down at the crowds in a moment of reflective connection while a small moment of chaos occurred behind her.

'Charles appeared keen to take an early exit from the balcony, throwing one final wave and turning to go inside, before William reminded him that they were about to play the national anthem. 

'It was Charlotte standing serenely holding the fort at the front of the balcony while the others chatted behind her.

'She looked down at the crowds as though really acknowledging her own subjects with a closed-lip smile of affection, a facial expression that she appeared to have inherited from the late Queen and the Queen Mother,' insisted Judi.

The body language expert claimed that Charlotte also led the 'choreography' as she walked out onto the balcony directly behind the King.

'Charlotte directed Louis to go off to the side, pointing with both hands to the place where he needed to stand in a gesture normally seen in a TV studio as guests are shown to their spots,' said Judi.

She added: 'Kate ushered George to join the others with one gentle hand on his back and Charlotte took over by checking to see he'd found his spot, too.

'It was telling how George sidestepped quickly to stand closer to his mother where they smiled and chatted like friends as well as parent and child. 

'William rather firmly took over the choreography though, beckoning Charlotte to come closer to him and stand in front with Louis.'

Meanwhile, Prince Louis delighted royal fans with his antics as the King's official birthday celebrations were completed with a Red Arrows flypast.

Charles’ anniversary was celebrated with a display of military pomp and pageantry that showcased the best of the Army’s ceremonial prowess on Horse Guards Parade in front of the Royal Family and thousands of spectators.

All eyes were on the Prince and Princess of Wales youngest child Louis, who is famed for his playful nature on big royal occasions.

He was spotted ducking down to look through a half-open window to catch a glimpse of Trooping the Colour, and later leaning sideways to get a better view of the celebratory fly-past.

The eight-year-old prince was watching events from the first-floor window of the Duke of Wellington’s former office with his siblings and other royals including the Duchess of Edinburgh and Vice Admiral Sir Tim Laurence.

Below in the parade ground on a royal dais were the King, Queen and Kate, who wore a striking wide-brimmed blue and white Philip Treacy hat and matching Catherine Walker outfit.

The royal women paid tribute to their regiments, with Kate sporting the brooch of the Irish Guards, of which she serves as Colonel, while Camilla is Colonel of the Grenadier Guards and wore a red Fiona Clare dress based on their uniform and a black beret with white plume by Treacy, featuring her regimental cap badge.

Trooping the Colour is a historic ceremony where colours, or regimental flags, used as rallying points in battle were 'trooped' or paraded in front of soldiers so they would be recognised, leading to them taking on great symbolic importance as the heart and soul of a regiment.

The ceremony evolved into a celebration of the head of state’s official birthday and this year the colour trooped was the King’s Colour of the Grenadier Guards, presented by the King earlier this week during a Buckingham Palace ceremony.

Trooping is as much a social occasion as a ceremonial event and stands around Horse Guards Parade were filled with about 8,000 family members of the guards and officers on parade.

In summer sunshine, Charles inspected the troops from a carriage, passing the ranks of just over a thousand guardsmen from the Grenadier, Scots, Irish and Coldstream Guards regiments and later stood to salute as the colours were marched past him, first slow then in quick time by the servicemen.

The national celebration is one of the highlights of the royal calendar.

The Duke and Duchess of Gloucester and Duke of Kent were also gathered on the Buckingham Palace balcony for the traditional fly-past of RAF aircraft.

The aerial display roared over the palace in 10 waves and featured Typhoon jets, Chinook helicopters, C-17 large military transport planes and the Red Arrows trailing their trademark red, white and blue smoke and joined by four F35-B short take-off and vertical-landing jets.

Crowds had gathered in The Mall to see the Royal Family but the area directly in front of Buckingham Palace was kept free of spectators.