Queen Elizabeth II dies - follow the latest news as the world mourns
The transition of power from one monarch to the next is inevitably a challenging period.
The timing of Queen Elizabeth's death is more unstable, however, than when her father, King George VI, died in the relatively quiet year of 1952.
King Charles III inherits the title at a time when there is war in Europe, rampant inflation and soaring energy costs. Furthermore, a new prime minister, Liz Truss, has been in the post for only a few days.
Generations of Britons have known no other monarch than Queen Elizabeth, and the loss of a figurehead with such experience and gravitas would be troubling to many.
Britain’s civil service has already moved into transitional planning with all the government department heads, known as permanent secretaries, meeting on Thursday afternoon.
The protocol has been in place for decades: the instant the queen died, Prince Charles immediately became King Charles III.
He is the oldest British monarch to inherit the throne, but also the one with the most experience of having been heir apparent.
While Britain’s head of state is the monarch, in reality nearly all power resides with the prime minister and her government. This makes the transition of power not as perilous as it has been in past British history, when at times war has broken out upon a sovereign’s death.
Queen Elizabeth provided the country and the Commonwealth with an unprecedented 70 years of continuity and her passing still presents pitfalls. She gave counsel to 15 prime ministers throughout her reign, even in her final days when she met Ms Truss at Balmoral this week. Without her there will be novices in Buckingham Palace and Downing Street.
When her father died, the veteran wartime prime minister Winston Churchill was back in office to provide the 25-year-old queen with a political rock to rely upon.
Prince Charles has also taken on an increasing number of royal roles, most notably reading the queen’s speech to Parliament in May. This is the most important constitutional moment when the monarch sets out Downing Street’s political agenda while referring to “my government”.
He has also stood in for his mother at the Maundy Thursday church service in Windsor as she missed public events over Easter and at the Cenotaph Remembrance Day service in November.
With the transition of power already under way, it is hoped that the new king would be welcomed both at home and abroad.
That would be helped by a number of immediate and rehearsed actions that ensure it occurs without significant mishap.
An “accession council” has been formed from the group of advisers known as the Privy Council and will meet at St James’s Palace in London.
There, the Privy Council will formally recognise the transition from one monarch to the next and officially pronounce Charles as king.
He will then take an oath inheriting the title: “Charles the Third, by the Grace of God, of the United Kingdom of Great Britain and Northern Ireland, and of His other Realms and Territories King, Head of the Commonwealth, Defender of the Faith”.
Parliament will be recalled, with MPs and Lords taking a new oath of allegiance to the king.
It is unknown when exactly Prince Charles would first be seen in public as the new king, but he is likely to make a TV address on Friday evening. He gave a statement shortly after her death cherishing his “beloved mother”.
As heir apparent, Prince William will now be known as the Duke of Cornwall and Cambridge, assuming his father’s titles and then, in a formal investiture, Prince of Wales.
The queen has always stayed above politics but Charles has discreetly taken a more proactive role. He is unlikely to remain impartial on his most importantly held subjects of climate change, architecture, organic farming and conservation.