The Queen of England has been placed under medical supervision at Balmoral after doctors became concerned for her health, Buckingham Palace has said.
All the Queen’s children are gathering at her Scottish estate near Aberdeen.
“Following further evaluation this morning, the Queen’s doctors are concerned for Her Majesty’s health and have recommended she remain under medical supervision,” a statement said.
The Queen is “comfortable”, it added.
The BBC reports that it is very unusual for Buckingham Palace to put out a statement like this – it is usually unwilling to provide a commentary on the 96-year-old monarch’s medical matters, which are seen as private.
It said her son, Prince Charles, is at Balmoral with his wife, Camilla, the Duchess of Cornwall.
Her grandson, the Duke of Cambridge, other sons, the Duke of York and the Earl of Wessex, and his wife Sophie, the Countess of Wessex, also arrived at Aberdeen airport just before 16:00 BST.
Prince William drove them alone in a car together to the Queen’s Scottish estate, a journey of about 40 miles (64km).
Her daughter Princess Anne was already in Scotland undertaking engagements and is in Balmoral.
The Duchess of Cambridge has remained in Windsor with her children on their first full day at school.
The Duke of Sussex is travelling separately to Balmoral. A spokeswoman said his wife Meghan was not accompanying him.
The US-based couple had been in the UK to attend a charity function.
There are pressing concerns for the Queen’s health – much more explicitly put than before and without any reference to this only being about difficulties with mobility.
On Tuesday she was photographed smiling as she appointed new Prime Minister Liz Truss.
But from the last-minute cancellation of what would only have been a virtual meeting of the Privy Council – of senior ministers – there is no mistaking the fragility of the Queen’s health.