Tuesday, the day before his famous D-Day address that brought Queen Camilla to tears, King Charles was rushed to a London hospital for his cancer treatment amid his health issues.

The King attended the event; however, according to medical advice, his "carefully calibrated" attendance was cut short by 45 minutes. The King was given the all-clear by his medical team to perform his Royal duties in April.

It is believed that doctors suggested "compromises," which resulted in Prince William standing in for his father at the celebration on Omaha Beach in France.

According to royal insiders, all the events attended by Charles were reviewed in cooperation with doctors. “They were extremely long days and some compromises had to be made.”

Meanwhile, Prince William's close aide informed that the Prince of Wales has a strong desire to assist his father, both in the UK and abroad.

Addressing an emotional gathering of veterans during a national commemorative event in Ver-sur-Mer on Thursday, the monarch expressed his "profound sense of gratitude" to the army heroes who served in 1944.

Both King and Queen got emotional as Camilla wiped her eyes when a war-veteran read out his heart-touching story to the crowd.

When one soldier asked King Charles about his health, the monarch assured that he is "doing well".

The King paid a homage to the "remarkable wartime generation," reminding the audience, "It is with our most profound gratitude that we remember them and all who served at that critical time."

The Prince of Wales honoured soldiers who served "for our freedom" at a Canadian anniversary service on Juno Beach, saying, "All of you demonstrated heroism, and determination, that ensured fascism was conquered."

Charles is scheduled to attend King's Foundation Awards next Tuesday, June 11, at St James' Palace in London.

Moreover, the monarch intends to take part in his birthday parade, known as Trooping the Colour, on June 15. While Princess Kate, who missed an important royal event as Colonel of the Irish Guards on Saturday owing to cancer treatment, is unlikely to appear on Buckingham Palace's balcony this year.