After the year they have had, it was probably as close to the ‘new normal’ for the Royal Family that we are going to get, for the time being at least.

Naturally all eyes were on the Princess of Wales as she returned to the public eye in her most significant official role since she effectively withdrew from royal life at the start of the year following her shock cancer diagnosis.

Her warm smile and dazzling sense of style made us all realise how much Kate had been missed, even if this particular princess wasn’t quite up to going to ‘the ball’ (aka the State Banquet).

MailOnline understands that this is all part of her ‘gradual’ and measured return to work, balancing her commitments generally, but also specifically this week between the State Visit and her own annual carol service on Friday.

It was still a tonic, however, to see her looking so happy and well, Prince William just once discreetly laying a comforting hand on her shoulder but otherwise happily letting his wife get on with what she does best - shine.

There were other ‘tweaks’ too throughout the day, most notably for Queen Camilla, who had been forced to pull out from the official ceremonial welcome on Horse Guards as she is still suffering from the side-effects of what we now know to be a nasty case of pneumonia.

Instead she met the royal party inside Buckingham Palace - a thoroughly sensible move for a 77-year-old suffering from such a debilitating viral infection in the circumstances - and announced an ever-so-slightly curtailed appearance at the evening’s glittering State Banquet.

Later, in the historic palace Picture Gallery, Old Masters looked down as the royal party examined a notably smaller display of artefacts from the Royal Collection - including the late Queen Elizabeth’s speech from Qatar’s State Visit in 2010 - than in previous years.

Kate's appearance at the Emir of Qatar's ceremonial welcome made us all realise how much the Princess of Wales had been missed, since she stepped back from public life for cancer treatment

Kate's appearance at the Emir of Qatar's ceremonial welcome made us all realise how much the Princess of Wales had been missed, since she stepped back from public life for cancer treatment 

It was a tonic to see Kate looking so happy and well, Prince William just once discreetly laying a comforting hand on her shoulder but otherwise happily letting his wife get on with what she does best - shine

It was a tonic to see Kate looking so happy and well, Prince William just once discreetly laying a comforting hand on her shoulder but otherwise happily letting his wife get on with what she does best - shine

Britain's future king and queen at an official royal engagement at Horse Guard's Parade on November 3

Britain's future king and queen at an official royal engagement at Horse Guard's Parade on November 3

Instead of several tables running a third of the length of the room, there were just two - as if the organisers were quietly keen to keep things moving at slightly more rapid pace.

All this might seem insignificant to the untrained eye, but in royal parlance it’s these tiny details that often paint the bigger picture.

It’s important to stress that this is not a portrait of doom and gloom - far from it.

Cast your mind back to the start of the year when King Charles and Kate were hospitalised simultaneously - he for a prostate condition and she for serious abdominal surgery.

The blows continued to come thick and fast: within weeks we not only learnt that doctors had diagnosed an unconnected form of cancer in the monarch, but the princess revealed that she, too, had been told that cancer had been present and that at the age of just 42 she needed to undergo a course of preventative chemotherapy.

The nation was left punch-drunk with shock, so soon after the loss of the steadying influence of Queen Elizabeth and the doughty stoicism and seemingly unending longevity of Prince Philip, the Duke of Edinburgh.

So in fact it is utterly remarkable that within less than a year of these seismic - and potentially catastrophic - events that we have almost all members of our Royal Family on duty simultaneously at such a diplomatically crucial event.

But it does also go to emphasise that, for the time being at least, we may have to cut them a little slack.

The Royal Family turned out in full force today to welcome the Emir of Qatar, Sheikh Tamim bin Hamad Al Thani, and his wife, Sheikha Jawaher (Pictured left to right: The Princess of Wales, Prince William, King Charles, the Emir of Qatar, Sheikh Tamim bin Hamad Al Thani, and his wife, Sheikha Jawaher)

The Royal Family turned out in full force today to welcome the Emir of Qatar, Sheikh Tamim bin Hamad Al Thani, and his wife, Sheikha Jawaher (Pictured left to right: The Princess of Wales, Prince William, King Charles, the Emir of Qatar, Sheikh Tamim bin Hamad Al Thani, and his wife, Sheikha Jawaher)

All eyes were on the Princess of Wales as she returned to the public eye in her most significant official role since her shock cancer diagnosis earlier this year (She is pictured alongside Prince William at the Horse Guards Parade today)

All eyes were on the Princess of Wales as she returned to the public eye in her most significant official role since her shock cancer diagnosis earlier this year (She is pictured alongside Prince William at the Horse Guards Parade today)

A source tells me: ‘It’s just a question of adaptions given the particular challenges of this year. I don’t think this is a sign of things to come but it is necessity of where we find ourselves at this moment in time.’

Indeed, at a time when recent discussions have focused more heavily than ever on both the function of our monarchy, as well as its funding, yesterday’s State Visit has emphasised more than ever why it is still, in diplomatic terms, our trump card.

One senior Qatari diplomat told me recently that we should not underestimate the importance that their Emir, - was educated in the UK and commissioned at the Sandhurst military college, and could be seen beaming from ear-to-ear throughout the day - has placed upon it.

Indeed, it is considered something of a coup for his country to be the first Middle Eastern state to be afforded the honour.

This is of no small significance in Whitehall where mandarins appreciate more than anyone the importance of the longevity of the Royal Family’s friendship with countries such as Qatar (which is currently heavily investing in British science and technology) particularly given the level of political instability we have seen in the UK in recent years.

King Charles and Sheikh Tamim bin Hamad Al Thani were pictured while inspecting a Guard of Honour

King Charles and Sheikh Tamim bin Hamad Al Thani were pictured while inspecting a Guard of Honour

Kate's warm smile and dazzling sense of style were missed. She is pictured in a stunning burgundy ensemble for the elite occasion

Kate's warm smile and dazzling sense of style were missed. She is pictured in a stunning burgundy ensemble for the elite occasion

The Emir of Qatar, Sheikh Tamim bin Hamad Al Thani and his wife Sheikha Jawaher arrive for a tour of Westminster Abbey earlier today

The Emir of Qatar, Sheikh Tamim bin Hamad Al Thani and his wife Sheikha Jawaher arrive for a tour of Westminster Abbey earlier today

Queen Camilla met the royal party inside Buckingham Palace following lingering side effects from a nasty case of pneumonia

Queen Camilla met the royal party inside Buckingham Palace following lingering side effects from a nasty case of pneumonia

The King and Qatar's Emir Sheikh Tamim bin Hamad Al Thani inspect a Guard of Honour

The King and Qatar's Emir Sheikh Tamim bin Hamad Al Thani inspect a Guard of Honour

King Charles travels in the Irish State Coach with the Emir of Qatar Sheikh Tamim bin Hamad Al Thani and his wife Sheikha Jawaher along The Mall to Buckingham Palace today

King Charles travels in the Irish State Coach with the Emir of Qatar Sheikh Tamim bin Hamad Al Thani and his wife Sheikha Jawaher along The Mall to Buckingham Palace today

The Princess of Wales attends the ceremonial welcome at Horse Guards Parade today

The Princess of Wales attends the ceremonial welcome at Horse Guards Parade today

It’s worth noting that we are now on our seventh Prime Minister in under a decade, and only our second head of state in 70 years.

And at the heart of it all is the King, a man who, while ‘living with cancer’, still undergoing weekly treatment in London for the foreseeable future, has stoically been out on manoeuvres from morning until night.

He heads a new-look Royal Family, one that is smaller and, yes, slightly more vulnerable than before, but has nevertheless has demonstrated more than ever this week its continuing relevancy.

Just in a slightly different way than before.