Queen Elizabeth II dead at 96
Queen Elizabeth II (Frank Augstein POOL/AFP)

The reign of Britain's longest-serving monarch came to an end on Thursday when it was announced Queen Elizabeth II had died at the age of 96. It is presumed that Prince Charles, her eldest son, will assume the crown.

"The Queen died peacefully at Balmoral this afternoon. The King and The Queen Consort will remain at Balmoral this evening and will return to London tomorrow," the royal family said in a statement.

On Tuesday, Queen Elizabeth postponed a meeting of her Privy Council advisory group after doctors advised her to rest, Buckingham Palace said Wednesday, the day after she appointed Liz Truss as Britain's new prime minister.

"After a full day yesterday, Her Majesty has this afternoon accepted doctors' advice to rest," the palace said in a statement.

"This means that the Privy Council meeting that had been due to take place this evening will be rearranged."

The 96-year-old monarch, who was on her traditional summer retreat at Balmoral in the Scottish Highlands, has been dogged by problems walking and standing since last year, forcing her to cancel a series of public engagements.

Fears about a flare-up of what royal officials call "episodic mobility problems" prevented her returning to London to accept outgoing leader Boris Johnson's resignation and to appoint Truss on Tuesday.

The constitutional role -- the so-called "kissing of the hands" ceremony -- usually takes place at Buckingham Palace in London.

It was the first time it had been held outside London since 1952, when Winston Churchill met the new queen at Heathrow Airport after the death of her father, George VI.

Last week, Elizabeth skipped the Highland Games event, a traditional highlight of her summer in Scotland.

The latest cancellations revived concerns about her health.

She was also hit by a bout of Covid earlier this year, that she said left her "exhausted."

With additional reporting from AFP.