Kate Middleton honors the memory of the recently deceased Queen while greeting the Emir of Qatar.

The Princess of Wales looked regal in a berry ensemble as she took on her most significant royal engagement of the year this morning – and she carried the late Queen’s memory with her as she did so.

Kate, 42, donned a burgundy coat dress by Sarah Burton for Alexander McQueen (although recently departed for Givenchy) and matching hat from Sahar Millinery as she met the Emir of Qatar, Sheikh Tamim bin Hamad Al Thani of Qatar and the first of his three wives, Sheikha Jawaher, during a ceremony of pomp and pageantry in Horse Guards Parade, London.

Marking a huge moment for the Princess as she returns to this official engagement following months out of action while undergoing chemotherapy, Kate added a flash of glamour to the ceremonial welcome of the Qatari royals. In choosing berry, she echoed similar shades to those she sported in Southport in September when she visited families who had lost their three young daughters in a horrific knife attack in July.

The royal wore her hair in a chic and intricate updo as she arrived at Horse Guards Parade flanked by her husband Prince William; and chose significant jewels to mark the significant occasion. 

She donned the late Queen’s £30,000 Bahrain pearl drop earrings and her Japanese Pearl choker necklace, both of which were also previously worn by Princess Diana.

After fans noticed earlier in the autumn that the Princess’s engagement ring, which also once belonged to Princess Diana, had been replaced by an eternity ring, Kate wore the sapphire stone today.

In a break from her usual suede pumps in a matching shade, the Princess instead opted to wear a pair of leather berry boots. 

While Kate brought her signature elegance and glamour to the event, a notable absence was felt in Queen Camilla, who will miss some of the event scheduled for the two-day visit due to ill-health. 

Nonetheless the Princess of Wales’s involvement in this morning’s ceremony has been hailed as a ‘positive sign’ of her recovery in royal circles as she makes gradual steps back into public life. 

In addition to the official welcome on Horse Guards Parade, she will also be involved in the carriage procession back to Buckingham Palace, before attending a private lunch.

Kate will stay to view a display of priceless Qatari artefacts from the Royal Collection. The only aspect of the day she will miss will be tonight’s glittering state banquet.

A royal source described the announcement of the Princess’s attendance as ‘good news’ as the Princess continues with her a slow and measured return to public life after the completion of her preventative chemotherapy treatment.

Kate announced in March that she had embarked on a course of treatment after doctors found evidence of the disease after major abdominal surgery in January.

In September she revealed that this had now been completed but warned that it would take time and patience for her to return to full-time royal duties.

Now, today’s events mark the start of a busier week for Kate, who will be hosting her annual Christmas carol service at Westminster Abbey on Friday.

The Princess is expected to be joined at that event by her husband Prince William and children Prince George, Princess Charlotte and Prince Louis.

But Camilla has pulled out of today’s welcome at Horse Guards Parade on doctor’s advice because she is still suffering from the ‘lingering’ side-effects of a ‘nasty viral chest infection’.

The 77-year-old royal, who fell ill a month ago, is said to be feeling particularly ‘fatigued’ – but she will attend the lunch at Buckingham Palace and most elements of the State Banquet this evening.

So as not to exhaust her, she will greet their VIP guests and pose for photographs before retiring during a lengthy receiving line, but then join the dinner itself.

As for Camilla, sources stressed there was no cause for alarm, describing her as having had a ‘nasty viral chest infection’ which continues to ‘have some lingering side effects, in particular leaving Her Majesty with significantly diminished reserves of energy.’

As a result, they said, her doctors have advised some ‘tweaks’ to her programme.

Her decision not to join the King at Horse Guards Parade for a full ceremonial welcome and open-air carriage drive back to Buckingham Palace on a cold morning was a sensible precaution given the nature of her illness, they stressed.

Her diagnosis was first announced almost a month ago on November 5 when it emerged that she had been forced to pull out of the Field of Remembrance at Westminster Abbey, followed by other events over the weekend, including the Cenotaph, to honour the nation’s war dead.

As the daughter of a twice-decorated Second World War veteran, such duties are taken very seriously by the Queen – and her absence was a sign of how poorly she was feeling, sources close to her told the Mail.

Camilla has undertaken several public engagements since then, including the annual diplomatic reception, but has sometimes curtailed her time spent in public.

At a reception to honour the UK’s film and television industry last month, the Queen discreetly coughed several times during her shortened appearance and gratefully sipped on a glass of water, saying she had felt ‘absolutely rotten’ last week but was definitely ‘on the mend’.

Sources have stressed there has been ‘no alteration’ in any diagnosis or treatment being received, stressing Her Majesty just needs time to ‘rest and recover fully, which is more challenging with a back-to back diary programme such as the state visit’.

No substantial changes to her other diary commitments are expected the rest of the week, though each day is being taken as it comes.

Guidance from her medical team suggests that in such cases post-viral fatigue symptoms can come and go and persist for several weeks.

At tonight’s state banquet, Camilla will join photographs with the Emir and Sheikha Jawaher, but then retire briefly during the lengthy receiving line.

She will then attend the dinner as planned and join the King for the official farewells tomorrow.

Camilla has been praised for the way she has stepped up this year on behalf of her husband, after he was diagnosed with cancer at the start of the year and has continued to undergo treatment. Sources have described her as a ‘trooper’.

Today’s state visit is considered one of the highlights of the royal calendar and a show of royal ‘soft diplomacy’ in action.

Senior Qatari diplomats have told the Mail that they are ‘deeply honoured’ the King has chosen their country as the first Middle Eastern state to be invited for a full state visit to the UK since Charles’ accession.

The country enjoys a good relationship with the UK diplomatically, with the Emir, 44, having studied in Britain – first at Sherborne and then Harrow – followed by a stint at the Royal Military Academy at Sandhurst.

There remains great admiration for the late Queen Elizabeth II, and Charles has met with the Emir on several occasions.

The two countries also have strong trade, cultural and military links, and Qatar is a major investor in the UK, not just through property and construction projects, but in science and technology.

However concerns have been raised about the authoritarian nature of the Qatari ruling family and human rights, particularly as regards migrant workers.

The Emir, His Highness Sheikh Tamim bin Hamad Al Thani, will be bringing his first wife – and second cousin – Sheikha Jawaher bint Hamad Al Thani, with him on the visit.

She is the mother of four of his 13 children and normally accompanies him on official visits abroad. He also has two subsequent spouses.

The couple landed in the UK at London Stansted Airport yesterday where they were greeted on behalf of the sovereign by the Lord in Waiting, The Viscount Hood.

Today they will be officially welcomed by William and Kate at their residence, before being escorted to Horse Guards Parade where the King will be waiting for an impressive ceremonial welcome.

National anthems will be played and the Emir invited to inspect a Guard of Honour.

The royal party will then return in a carriage procession to Buckingham Palace for a private lunch followed by an exhibition in the Picture Gallery of items from the Royal Collection Trust and Turquoise Mountain charity relating to Qatar.

William will later receive the Emir at Kensington Palace before the evening’s state banquet, which he will attend but not his wife.

Tomorrow, the final day of the two-day visit, the Emir will visit Sandhurst before travelling to the Palace to bid farewell formally to the King.

Sheikh Tamim will also travel to Downing Street for bilateral talks with Prime Minister Sir Keir Starmer.

Kate has attended a number of high profile events such as Trooping the Colour, Remembrance Sunday and Wimbledon over the last 11 months since she effectively withdrew from public life to focus on her health.

But today’s appearance will be her most significant so far given that she will be playing a far more active role in events and be seen in public for a lengthy period of time.

Royal-watchers will be delighted at the news that Kate is taking a further step forward as part of her staggered return to full-time royal duties.

In September she spoke of her ‘relief’ at having finally completed her chemotherapy treatment, but stressed that the last nine months had been ‘incredibly tough’ for them as a family.

She was first admitted to hospital in January for what has only been described as major abdominal surgery.

However afterwards doctors found evidence that cancer had been present and recommended a course of preventative chemotherapy.

The couple chose to keep the news private for several weeks in order to come to terms with the news and protect their children, before the princess bravely went public with her diagnosis in March.

Talking of the ‘complex, scary and unpredictable nature’ of cancer journeys, Catherine said recently that doing what she could to ‘stay cancer free is now my focus’ and emphasised that her path to full recovery would be ‘long’.

The Princess said she would undertake a few more public engagements in the coming months when she could but stressed that her focus would remain on her continued recovery and her young family.