Queen Elizabeth II Photo:VCG

Family members rushed to be with Queen Elizabeth II after doctors said they were concerned about the health of Britain's 96-year-old monarch on Thursday and said she should remain under medical supervision.

The queen, Britain's longest-reigning sovereign and the world's oldest monarch, has been suffering from what Buckingham Palace has called "episodic mobility problems" since the end of 2021.

"Following further evaluation this morning, the Queen's doctors are concerned for Her Majesty's health and have recommended she remain under medical supervision," the palace said in a statement. "The queen remains comfortable and at Balmoral."

Her eldest son and heir Prince Charles and his wife Camilla have traveled to her Scottish home, Balmoral Castle, where she is staying, along with his eldest son Prince William, officials said. Her other children - Anne, Andrew and Edward - were also on their way.

A spokesperson said Prince Harry and his wife Meghan, in Britain for a number of events, would also travel to Scotland.

"My prayers, and the prayers of people across the @churchofengland and the nation, are with Her Majesty The Queen today," Justin Welby, the Archbishop of Canterbury, said on Twitter.

In October 2021, Elizabeth spent a night in hospital and she has been forced to cut back on public engagements since then. On Wednesday she canceled a virtual meeting with senior ministers after being advised to rest by her doctors.

The previous day she had been pictured appointing Liz Truss as the country's new prime minister at Balmoral.

A palace source played down speculation that the monarch had suffered a fall.

Elizabeth has been queen of Britain and more than a dozen other countries since 1952, including Canada, Australia and New Zealand, and earlier in 2022 marked her 70th year on the throne with four days of national celebrations in June.

"I have been inspired by the kindness, joy and kinship that has been so evident in recent days, and I hope this renewed sense of togetherness will be felt for many years to come," she said at the time.

Elizabeth came to the throne after the death of her father King George VI on February 6, 1952, when she was just 25.

She was crowned in June the following year. The first televised coronation was a foretaste of a new world in which the lives of the royals were to become increasingly scrutinised by the media.

She became monarch at a time when Britain retained much of its empire. 

Winston Churchill was the first prime minister who served during her reign. Truss is the 15th premier of her record-breaking reign.

The prime minister said: "My thoughts - and the thoughts of people across our United Kingdom - are with Her Majesty The Queen and her family at this time."

Reuters