UPDATE 8-King Charles proclaimed monarch, queen's funeral on Sept. 19

* Charles officially proclaimed king

* Queen's funeral set for Sept. 19

* 'We thought she was invincible' - William

* Queen Elizabeth, 96, died on Thursday (Adds William, Harry, quotes)

By Michael Holden and Kate Holton

LONDON, Sept 10 (Reuters) - The state funeral for Queen Elizabeth will be held on Monday, Sept. 19, royal officials said on Saturday, as her son Charles was officially proclaimed Britain's new king in a colourful ceremony laden with pageantry and dating back centuries.

The death of the 96-year-monarch has provoked tears, sadness and warm tributes, not just from the queen's own close family and many Britons, but also from around the world - reflecting her presence on the world stage for 70 years.

"We all thought she was invincible," said her grandson Prince William https://www.reuters.com/world/uk/prince-william-pledges-support-king-charles-every-way-he-can-2022-09-10, now the heir to the throne.

"It's been surreal," he said during a walkabout outside Windsor Castle where he and his wife Kate appeared closely in public for the first time in two years with his younger brother Harry and his wife Meghan - a sign Elizabeth's death might help heal a rift between Charles' sons.

Elizabeth's oak coffin, covered with the royal standard of Scotland and with a wreath of flowers on top, has been lying in the ballroom of Balmoral Castle, her summer home in Scotland where she died peacefully on Thursday.

On Sunday, it will be driven by hearse https://www.reuters.com/world/uk/plans-run-up-queen-elizabeths-funeral-2022-09-10 through remote highland villages to Scotland's capital, Edinburgh, during a six-hour journey that will allow people to pay their respects.

The coffin will then be flown to London on Tuesday where it will remain at Buckingham Palace before being taken to Westminster Hall to lie in state until the funeral at Westminster Abbey at 11 a.m (1000 GMT) on Sept. 19.

The death of Elizabeth, Britain's longest-reigning monarch, has prompted an outpouring of emotion around the globe. Buildings and landmarks in Europe, America and Africa have been lit up in the red, white and blue of the United Kingdom's flag.

Charles, 73, immediately succeeded https://www.reuters.com/world/uk/process-by-which-charless-accession-throne-is-formalised-2022-09-08 his mother but an Accession Council met at St James's - the most senior royal palace in the United Kingdom built for Henry VIII in the 1530s - to proclaim him as king on Saturday.

The council - formed of Privy Counsellors whose centuries-old role has been to advise the monarch - included his son and heir William, wife Camilla and Britain's new prime minister, Liz Truss, who signed the proclamation of his accession.