The King and Queen are commemorating the life and service of Queen Elizabeth II at Crathie Kirk.
Charles, dressed in a red tartan kilt, and Camilla, in a blue day dress and cardigan, made the short journey by car from the nearby Balmoral Estate to the Scottish church where monarchs have worshipped since Queen Victoria.
On the first anniversary of the death of Queen Elizabeth II, the King and his wife are marking her life with private prayers and a moment of reflection.
They were joined by the late Queen’s niece and nephew, Lady Sarah Chatto and the Earl of Snowdon.
Elizabeth II was close to her sister Princess Margaret’s children, especially Lady Sarah who she saw often.
The earl was accompanied by his daughter Lady Margarita Armstrong-Jones, and Lady Sarah by her husband Daniel and children Samuel and Arthur.
Former dean of the Chapel Royal in Scotland Iain Torrance was giving the sermon.
A small group of Balmoral estate workers and members of the public had gathered close to the church whose minister is the Rev Kenneth MacKenzie.
Some of the men were dressed in kilts and a number of the women wore tartan in the bright autumn sunshine, and were joined by a handful of pupils from Crathie Primary School.
Crathie Kirk was first attend by Victoria, the great-great-grandmother of Elizabeth II, in the late 1840s.
The event will be a deeply personal moment for the King, who became sovereign when his mother died peacefully on September 8 last year at Balmoral, aged 96, after reigning for 70 years.
The Prince and Princess of Wales, who will visit the Welsh cathedral of St Davids for a short private service on Friday, paid a personal tribute to the late Queen on the anniversary, saying: “We all miss you.”
The message written by William and Kate on X, formerly known as Twitter, read: “Today we remember the extraordinary life and legacy of Her Late Majesty Queen Elizabeth. We all miss you. W & C.”
It was accompanied by a family photo of the late monarch surrounded by her great-grandchildren including Prince George, Princess Charlotte and Prince Louis and her two youngest grandchildren.
The Waleses were pictured on the Buckingham Palace balcony with the late Queen and Charles during the Platinum Jubilee celebrations, with another image of the Queen dressed in a vibrant blue coat and hat.
The King has also recorded a message and released a favourite photograph of his mother.
Charles, in words written and audio spoken at Balmoral Castle, said he recalled with “great affection her long life, devoted service and all she meant to so many of us”.
He said: “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.”
The formal colour photograph chosen by Charles was taken by Cecil Beaton and shows her aged 42 in 1968.
She is standing sideways and smiling in her Garter robes and wearing the Grand Duchess Vladimir’s Tiara, made of 15 interlaced diamond circles.
Prime Minister Rishi Sunak also paid tribute to her “extraordinary life of duty and dedication” and said he treasured his memories of meeting the late Queen and was struck by her “wisdom, by her incredible warmth and grace” and her “sharp wit”.
Former prime minister Liz Truss has spoken about her final encounter with the late Queen , describing how the “upbeat” and frail but “mentally alert” monarch told her they would be “meeting again soon”.
Queen Elizabeth II welcomed Ms Truss to her home in Aberdeenshire on September 6 last year to appoint her prime minister.
“She was very, very keen to reassure me that we’d be meeting again soon. It was very important to her,” Ms Truss told GB News.
“She was very determined to do her duty, right to the end.”
Queen Elizabeth II died two days later and an emotional 11 days followed as the London Bridge plans swung into action, with a lying in state, vigils and a grand state funeral, all played out on a public stage.
Soldiers and horses who took part in the state funeral procession and proclamation salutes for the new reign will return for Accession Day gun anniversary salutes in the King’s honour.
Captain Amy Cooper, who was the lead rider in the procession that carried the coffin to lie in state in Westminster Hall, will give the order to fire a 41-gun salute at midday in London’s Hyde Park.
A 62-gun salute will also be fired at the Tower of London by the Honourable Artillery Company. The regiment and the King’s Troop were responsible for gun salutes after the death of Queen Elizabeth II.
Bells will be rung at Westminster Abbey at 1pm in commemoration of the King’s accession.