The Queen has faced a series of health scares. Photo / Getty Images
The Queen has not attended the Remembrance Sunday service at the Cenotaph after spraining her back.
The 95-year-old monarch has been under doctors' orders to rest for almost a month, and was scheduled to return to royal duties in central London on Sunday.
But she has injured herself at Windsor Castle, meaning she will stay there and has missed the service.
A Buckingham Palace spokesman said on Sunday morning: "The Queen, having sprained her back, has decided this morning with great regret that she will not be able to attend today's Remembrance Sunday Service at the Cenotaph.
"Her Majesty is disappointed that she will miss the service.
"As in previous years, a wreath will be laid on Her Majesty's behalf by The Prince of Wales.
"His Royal Highness, along with The Duchess of Cornwall, The Duke and Duchess of Cambridge, The Earl and Countess of Wessex, The Princess Royal and Vice Admiral Sir Tim Laurence, The Duke and Duchess of Gloucester, The Duke of Kent and Princess Alexandra will be present at the Cenotaph today as planned."
It is understood that the Queen's back sprain is unrelated to her medical team's recent advice to rest, and that she has not received hospital treatment for the injury.
The Telegraph understands Her Majesty is deeply disappointed to miss the service, which she regards as as one of the most significant engagements of the year.
A source said: "It is obviously incredibly unfortunate timing, and nobody regrets the Queen's absence today more deeply than Her Majesty herself."
The Queen hopes to continue her planned schedule of light duties next week.
Others, including the Prime Minister Boris Johnson and other members of the Royal family arrived for the service on Sunday.
Her Majesty has not missed the Cenotaph service since 1999, when she was on an overseas visit to South Africa.
Her return to public duties was due after she was compelled to pull out of a planned visit to Northern Ireland for health reasons on Tuesday, Oct 19. It later emerged she had spent the night in hospital undergoing tests.
She was unable to attend Cop26, where she had hoped to press delegates on the urgent need for action on the environment, and was already confirmed to be missing the Festival of Remembrance at the Royal Albert Hall on Saturday.
The Queen has always placed huge emphasis on her gratitude and respect for military veterans and their families.
Living through the Second World War herself, she has in recent years found herself among the oldest of those attending the Remembrance Sunday service, leading tributes from a balcony overlooking the Cenotaph.
Until the age of 91, she laid a wreath, only passing that symbolic duty over to the Prince of Wales in 2017.
The Queen has previously missed the Cenotaph service four times because she has been overseas on tours - in 1961, 1968, 1983 and 1999, and twice before the births of her two younger children.
Buckingham Palace had said it was the Queen's "firm intention" to attend the annual wreath-laying service in Whitehall.
The monarch is head of the Armed Forces and attaches great importance to the poignant service and to commemorating the sacrifices made by fallen servicemen and women.