Catherine returns as the Royal family unite at a Trooping like none before

Prince George, Princess Charlotte and Prince Louis watched the flypast. The Prince and Princess of Wales watched them.

The King kept an eye on his daughter-in-law, leaning in to make conversation time and again as she made her very public return to the spotlight.

The Queen jollied her husband along, declaring it all “wonderful”.

And, as Trooping the Colour drew to a close, the Duchess of Edinburgh patted Prince William reassuringly on the shoulder as the family walked back into Buckingham Palace together.

“Well done, everyone,” the King said.

Tactile, together, and very human, this was a Royal appearance like no other: the family reunited against the odds.

There had been no guarantee that either the King or the Princess of Wales would make an appearance at the monarch’s official birthday parade this year, both having had gruelling medical treatment after cancer turned their lives upside down.

In the end, under heavy rain and the glare of the world’s media, they put on a show for the ages, keeping up a tradition so central to national life and honouring the Armed Forces as they did so.

Even if the photographs made it look effortless, it was not without effort.

It was the culmination of weeks of planning behind the scenes, with the King determined to make it by hook or by crook, and the Princess desperate to support her family if she felt able.

Although preparations had been made in private, Catherine’s decision was not made public until less than 24 hours before Trooping the Colour began.

And it was only taken after the Princess, who says she has “good days and bad days”, judged she had enough energy for the long outing.

“We don’t deal in ‘what ifs’,” said a Palace source, pointing out that while the Princess had been keen to support her family, she could not be sure until the day that she was able.

The final decision, they added, was a reflection of her “huge amount of pride in the Irish Guards,” of which she is now Colonel, and the family that is the “front and centre” of her world.

The King, persuaded to travel by carriage rather than horseback in a concession to his own ill health this year, had been planning to attend since Easter. Trooping and D-Day were at the top of his wish list for public engagements as he continues with his cancer treatment.

The first glimpse of both came, in the end, in cars on their journeys from home into Buckingham Palace.

The Princess, travelling from Windsor, shared a back seat with her husband and Prince George, with Princess Charlotte and Prince Louis facing them as they waved and smiled their way through the gates to prepare for the big day.

Children wore co-ordinated outfits

Behind the scenes, as shown later in a video released by Kensington Palace, the Princess rearranged her daughter’s hair as the children – in coordinated, military-themed outfits – waited nervously for their carriage to arrive.

Lady Louise Mountbatten-Windsor was the first of the family to be seen on the official parade, sitting upright and poised in the first carriage while the Duchess of Edinburgh and the Duke of Kent sheltered under the heavy rain hood.

The Duke and Duchess of Gloucester and Vice Admiral Sir Tim Laurence came next, while his wife the Princess Royal rode as Gold Stick in the procession.

She was mounted on Noble, the black mare given to the King by the Canadian Mounties, and which gave him a little skittish trouble when he rode last year.

The Prince of Wales and Duke of Edinburgh were on horseback too, the former only just recognisable under the bearskin of his ceremonial uniform of the Welsh Guards.

Then, in the Scottish State Coach, came the King and Queen. In the Glass State Coach behind them, the young Wales children smiled and waved to the crowds; by now veterans of the journey and the cheering crowds lining the streets.

The Princess of Wales in a white Jenny Packham dress with a black bow and a regimental brooch of the Irish Guards, kept up a smiling stream of conversation with her children.

As they reached Horse Guards Parade, the children leapt out, revealing knee-high socks for Louis, and Charlotte in white shoes to match her mother. The Princess followed, only the most eagle-eyed seeing a brief hand to her stomach as she straightened up in high heels to stride into the building.

As the long-rehearsed spectacle of Trooping the Colour began in earnest, the King and Queen took their places on a dais, with the non-riding members of the family watching from the Major General’s Office above.

The stamina required for the 75-year-old King to stand throughout the ceremony would not have been lost on those watching on.

Pushing himself to the limit through ill health for duty, he did so admirably, taking the salute and inspecting the 1,250 troops marching past just as he has seen his forebears do since his first Trooping attendance at the age of two.

The regimental flag trooped was the King’s Colour of number 9 company, Irish Guards.

On the balcony above, Prince Louis danced to the sounds of Highland Laddie. The Princess of Wales stood with her children for nearly an hour before eventually sitting down at the window of the Duke of Wellington’s former office.

As the ceremony drew to a close and the senior members of the Royal family returned to their carriages, the heavens opened in what was described by onlookers as “Biblical” rain.

Puddles formed around the parade ground, and the Sovereign’s mounted escort, formed by troops from the Household Cavalry’s Life Guards and Blues and Royals, put their best hooves forward for the journey back to Buckingham Palace.

In the rear rank was Tennyson, one of the five horses injured when they ran through the streets of London after being spooked by construction noise while on a training exercise in April.

The King was seen talking animatedly to the Queen inside their carriage, visibly cheered as he saw the crowds still lining the streets on his route home.

Inside the Wales carriage, the windows steamed up, with the Princess of Wales and Princess Charlotte using their hands and sleeves to wipe away the condensation to see and be seen.

King looked drained, but resolute

At the gates of Buckingham Palace, the King once again stood, looking a little drained but resolute in completing his duties.

Shortly before 1pm, a sea of umbrellas – members of the public sheltered out of sight beneath them – surged up the Mall towards the palace, ready for the defining moment of the day.

It could not have looked more British, the television commentators remarked earnestly.

Moments before the Royal family stepped out onto the Buckingham Palace balcony ready for the flypast, the clouds cleared to reveal a blue sky.

As sunshine followed storms, the King and his supporting cast appeared –  a metaphor not lost on those who have worried about the Royal family’s challenges this year.

To cheers from the crowd below, the working members of the Royal family waved and looked around them, taking it all in.

If they had seen the sight countless times before, it would have had new resonance this of all years.

The King and Princess stood next to each other, taking it in turns to lean in for warm conversation.

The Queen and Duchess of Edinburgh chatted animatedly on his other side, with Prince Edward and Lady Louise facing forwards.

The rest of the working family – Princess Anne, the Duke of Kent and the Gloucesters – were at the far edges of the balcony; cut from most of the photographs of the day, but recognised for their solid, ever-reliable work for The Firm nevertheless.

With the King at the centre, waving repeatedly and appearing a little emotional, the Armed Forces flypast began.

Despite the rain, 34 RAF aircraft took to the skies, led by Chinook helicopters from No. 7 Squadron of RAF Odiham, and including helicopters, training, air transport, air-to-air refuelling, maritime, ISTAR, and fast jet combat aircraft from 15 squadrons and eight RAF stations. The flypast culminated with the Red Arrows.

The Battle of Britain Memorial Flight, grounded last month after the death of a pilot, was missing.

Prince George, Princess Charlotte and Prince Louis looked to the sky, with their parents leaning forward to chat with them about what they were seeing and check they were happy.

The Prince and Princess occasionally paused to look at one another and smile, and Catherine smoothed her daughter’s hair.

Louis, the youngest, kept himself entertained with the occasional dramatic head flick upwards to look to the skies.

A huge moment for the family

As God Save the King came to its close, the King permitted himself a small smile: of joy, of relief, of a new appreciation of these moments in the royal calendar he has seen so many times before.

“This is a huge moment for the family,” said one Palace source.

The Princess, in her personal statement to the public ahead of Trooping, said she had been “blown away by the kind messages of support”.

“It really has made the world of difference to William and me and has helped us both through some of the harder times,” she said.

For the Princess, the King and those who love them, the sight of the London crowds would have been an extra lift.

As they contemplate their next steps – a return to a busy schedule for the King; tentative steps for his daughter-in-law – they will now do so with the cheers of a public willing them on, ringing in their ears.