King Charles III is expected to address the nation for the first time as sovereign at 18:00 BST, following the death of Queen Elizabeth II.
Britain’s longest-reigning monarch died peacefully, surrounded by her family, at Balmoral in Scotland on Thursday.
The King is on his way to London, where he is also due to meet Prime Minister Liz Truss later.
Gun salutes will be fired and church bells have begun to toll as the UK pays tribute to her reign.
The bells of St Paul’s Cathedral, Westminster Abbey and Windsor Castle rang out at noon in tribute to her life and service.
There have been spontaneous gatherings and outpourings of emotion at Balmoral, Buckingham Palace and Windsor.
Members of the public have travelled to leave flowers, messages of thanks and condolence for the Queen and Royal Family, with many visibly tearful or overcome with emotion.
Union jacks are being flown at half mast and Lords and MPs have gathered to pay tribute to her momentous 70-year reign.
A gun salute in London’s Hyde Park has been arranged for the following hour, with 96 rounds to mark each year of her life to fire around 13:00 BST.
There will be a remembrance service at St Paul’s at 18:00 BST, attended by Prime Minister Liz Truss and other senior ministers.
It will be open to the public, with 2,000 tickets to be released on a first-come-first-served basis.
Those wishing to attend must visit in person to the City of London tourism office on Carter Lane in London to collect a wristband from 11:00 BST.(BBC)
