Prince Harry WILL return to Britain without wife Meghan for Invictus Games event for first time since Kate revealed she is undergoing cancer treatment - but will duke pay a visit to his once cherished sister-in-law?

Prince Harry is set to return to Britain in just a few days for the Invictus Games 10th anniversary in his first visit since Kate Middleton revealed her cancer diagnosis.

An Invictus Games spokesperson confirmed the Duke of Sussex will attend the Service of Thanksgiving at St Paul's Cathedral on Wednesday 8 May.

Actor Damian Lewis is also expected to recite the Invictus poem at St Paul's for the anniversary of the games for injured servicemen and women.

A statement published on the Invictus Games' social media read: 'The Invictus Games Foundation will celebrate 10 years of changing lives and saving lives with a 'Service of Thanksgiving' at St Paul's Cathedral on May 8th. 

'We will be joined by our Patron, Prince Harry, the Duke of Sussex, actor Damian Lewis and members of the worldwide Invictus Community to mark the occasion.'

However, Meghan Markle is not mentioned. As the event is just two days after their son Archie turns five, it is likely she will stay at home.

The pair live in Montecito, California with their two children, Archie, four, and Princess Lilibet, two.

The visit is the first time the Duke of Sussex has been in the UK since his last 26-hour trip in February, after his father King Charles announced his cancer diagnosis. 

It is unclear whether the prince is planning a visit to his sister-in-law, who recently revealed she is undergoing cancer treatment.

In her statement, the Princess of Wales revealed she had been diagnosed with cancer after 'planned abdominal surgery' in January.

The Duke and Duchess of Sussex were understood to have made contact with the Prince and Princess of Wales 'privately' after Kate announced her cancer diagnosis.

They also released a statement to Harper's Bazaar magazine, saying: 'We wish health and healing for Kate and the family.'

Last month Harry was in Canada for the Vancouver Whistler 2025's One Year to Go celebrations, which aimed to raise awareness of the 2025 Invictus Games, which will take place between February 8 and February 16 next year.

While in Canada, the Duke of Sussex spoke to Good Morning America reporter Will Reeve about King Charles's shock cancer diagnosis, his life with his family in California as well as his thoughts on becoming an American citizen.

The Duke of Sussex revealed he was 'grateful' to have seen his father Charles III in person during a brief 24-hour visit in the UK and hopes the diagnosis can have a 'reunifying effect' on the Royal Family. 

The nature of his trip, in which he shared a 'brief 45 minute meeting' with the King and Camilla and is not believed to have seen his brother William or sister-in-law Kate Middleton , shows how bad things have really become, royal expert Jennie Bond said previously.

He flew into London on a ten-hour flight from Los Angeles and arrived at the royal residence at 2.42pm before spending around 45 minutes with Charles.

This comes after the Duke of Sussex lost a High Court challenge against the Home Office over a decision to downgrade his taxpayer-funded personal security when he visits Britain.

Harry took legal action over the move by the Executive Committee for the Protection of Royalty and Public Figures (Ravec) after being told he would no longer be given the 'same degree' of publicly-funded protection when in the UK - which would include any Invictus Games-related visits. 

Harry and Meghan attended a preliminary event for the Invictus Games in the States last year.

The Prince, 39, launched the games back in March 2014 at the Copper Box arena in London and will see them being hosted in the UK again after the Government launched a £26million bid to host the event. 

Senior royals will need to take a stand on if they support the event, which they did at the first games in 2014 when then-Prince Charles, Camilla, and Prince William appeared alongside Harry for the opening ceremony.

But at the time, he was a full-time working royal - and any tensions and spats were not aired in public.

Since 2014, the Invictus Games have become a popular global sports competition which 22 countries and more than 500 athletes have been involved with.

It is an incredibly important piece of work for Prince Harry and one of his last remaining legacies from when he was a full-time working Royal - and one which he feels very proud of. The games also allow him to reconnect with fellow military veterans.

Earlier this month, Prince Harry updated his records in this country to make clear that he no longer lives in Britain.

Filings published by Companies House today for 'Prince Henry Charles Albert David Duke of Sussex' record that his 'New Country/State Usually Resident' is now the USA. It was previously recorded as the United Kingdom.

The move triggers questions as to whether the prince will stay in Frogmore Cottage for the duration of the games after the King asked him and his family to vacate.

It comes soon after it emerged that the King has been given permission by doctors to return to public-facing duties after being diagnosed with cancer.

His Majesty is not yet clear of the disease and is still undergoing treatment, but his medical team are understood to be ‘pleased with the progress made so far’ and ‘remain positive’ about his recovery.

To mark the good news Buckingham Palace have also announced two major milestone events, the first of many in the coming months, and passed on Their Majesties grateful thanks for all the good wishes they have received.

Kate and Charles are known to have formed a strong bond in the 13 years since her marriage to his son Prince William as she has been welcomed into the Royal Family.

And this relationship is said to have been 'cemented' by both senior royals being in for operations at the same time in January.

Kate made reference in her public video message to 'all those whose lives have been affected by cancer,' adding: 'You are not alone.' And this has been seen as a clear nod to Charles too.

She said she had delayed making any public announcement so that she and her husband Prince William could tell their three children Prince George, Princess Charlotte and Prince Louis.

Her statement came amid mounting speculation on the Princess' whereabouts in the months after her surgery.