By Michael Holden

LONDON (Reuters) - King Charles on Friday thanked the public for their "love and support" on the first anniversary of the death of his mother Queen Elizabeth and his accession to the throne, echoing her words as he vowed to be of service to all.

Elizabeth, Britain's longest-reigning sovereign, died aged 96 on Sept. 8 at Balmoral Castle, her beloved Scottish summer retreat, leading to 10 days of national mourning and condolences and tributes from across the world for her record-breaking 70-year reign.

Charles, who immediately succeeded her as king of the United Kingdom and 14 other countries including Canada, Australia and New Zealand, and his wife Camilla will spend the day privately and quietly at the Scottish royal home.

They are not due to attend any ceremonial event, nor will there be any large private family gathering to mark his 'Accession Day'.

"In marking the first anniversary of her late majesty’s death and my accession, we recall with great affection her long life, devoted service and all she meant to so many of us," Charles said in a statement.

"I am deeply grateful, too, for the love and support that has been shown to my wife and myself during this year as we do our utmost to be of service to you all."

Those latter words were an echo of the mantra that Elizabeth repeated throughout her reign.

"I remain committed to serving you to the best of my ability," she said at the end of celebrations to mark her Platinum Jubilee last June - her last major public event.

'SOLEMN'

While Charles is not due to make a public appearance, his eldest son and heir Prince William and wife Kate will attend a private church service to commemorate the queen's life.

William and Kate, the Prince and Princess of Wales, will visit the 12th Century St Davids Cathedral, a place of pilgrimage for centuries on the Welsh west coast which also has a special stall in the choir for the sovereign.

As is customary for such royal occasions, there will also be gun salutes fired in a London park and at the Tower of London. Prime Minister Rishi Sunak said the thoughts of the nation would be with Charles and his family on "the solemn anniversary".

"With the perspective of a year, the scale of her late majesty's service only seems greater," he said. "Her devotion to the nations of the United Kingdom and the Commonwealth only seems deeper. And our gratitude for such an extraordinary life of duty and dedication, only continues to grow."

Charles' low-key approach to the day is in keeping with how Elizabeth used to mark her accession, not regarding the event as something to celebrate as it was a reminder of the unexpected death her father George VI.

The queen's death last year marked an end of an era for Britain and, despite her age, came as a shock to the nation. During her seven decades on the throne, she had become not just Britain's figurehead but also a towering presence on the world stage.

She had worked right up until her passing, appointing Liz Truss as her 15th prime minister just two days before her death.

Charles first year on the throne has been dominated by his coronation, Britain's biggest ceremonial event for generations, full of pomp and pageantry.

Polls suggest most Britons have a favourable view of his reign so far, although younger generations appear much less enthusiastic.

He is also still dealing with issues within his own family, most notably the rift with his younger son Prince Harry and his wife Meghan, and what to do with his own younger brother Prince Andrew, who had to quit royal duties over his friendship with convicted sex offender Jeffrey Epstein.

"The bond between country and monarch is sacred," Sunak said. "It endures ... we should be proud that this remarkable legacy of service – and this remarkable bond – continues to grow today under the reign of his majesty the king."

(Reporting by Michael Holden; Editing by Alexandra Hudson)