The day Queen Elizabeth died: the inside story of her final hours

Balmoral Castle, despite its grand, gothic revivalist exterior, is intimate compared with Buckingham Palace and Windsor Castle, which is one of the reasons the late queen loved it. Its private quarters and official offices are quite close together.

Two days previously, leaning heavily on a stick but with that familiar smile in place, she had appointed her 15th and final British prime minister, Liz Truss. But an announcement just after 6pm the following evening, that the queen was postponing a virtual privy council meeting on the advice of doctors, was concerning.

Charles arrived at Balmoral shortly before 10.30am, and the Duchess of Cornwall was driven from nearby Birkhall to join him. The Princess Royal, in Scotland on engagements, was already there.

In No 10, Case was categorical that bad news was on its way, perhaps in a matter of hours. Truss had still not packed all her clothes for her move into Downing Street and, according to the biography Out of the Blue, aides were sent to her Greenwich home to locate black clothing.

When Buckingham Palace announced at 12.50pm that William, Andrew, Edward and Sophie were on their way to Scotland, the gravity of situation was very clear. At about 2pm, in a separate statement, the Sussexes, who were staying at Frogmore Cottage on a visit to the UK to attend an awards ceremony, announced that they, too, would be heading to Scotland.

There has been much speculation over why Harry did not accompany his brother and uncles onboard the jet that left RAF Northolt at 2.40pm. There have been suggestions the flight was originally intended to depart at 1.30pm. If that was the case, no reason has been given for the delay.

William and the other royals landed at Aberdeen airport at 3.50pm, 40 minutes after her death. With William at the wheel, they drove to Balmoral, arriving at 5.06pm, an hour and 25 minutes before the news would be made public.

By then, the official cascading of the news was in full swing. An internal palace team was calling all those who needed to be informed as soon as possible: No 10, Lambeth Palace, the chief of the defence staff, prime ministers and high commissioners of the 14 other countries of which she was head of state, to name but a few.

Harry finally arrived at Balmoral at 7.52pm. By then, Charles had released his own personal tribute to the late monarch, mother, grandmother and great-grandmother.

It was the end, too, of a truly historic day.