The monarchy's official social media accounts posted a congratulatory message with a more formal portrait of the King standing in the White Drawing Room at Buckingham Palace.
William and Kate's account shared an image of Charles in the sunshine during his recent long-haul overseas trip to Samoa as he was opening The King's Garden at the Robert Louis Stevenson Museum in Apia.
Wishing a very Happy Birthday to His Majesty The King! — The Prince and Princess of Wales (@KensingtonRoyal) pic.twitter.com/blN48K7490November 14, 2024
"Wishing a very Happy Birthday to His Majesty The King!" the message says.
Charles is treating his birthday as a normal working day and carrying on with his duties despite facing a personally challenging year in which both he and daughter-in-law Kate were diagnosed with cancer.
The King will open the first two Coronation Food Hubs on the first anniversary of the launch of his Coronation Food Project, designed to bridge the gap between food need and food waste in the UK amid the cost-of-living crisis.
The event will be a solo one for Charles, as the Queen recovers from a chest infection.
The King, in black tie, walked the red carpet on the eve of his birthday, meeting stars Denzel Washington, Paul Mescal and Pedro Pascal at the glitzy global premiere of Gladiator II.
King Charles met UK film heavyweights such as director Ridley Scott during a palace reception. (AP PHOTO)
On Wednesday afternoon, he hosted a special celebrity reception at Buckingham Palace in honour of the UK's film and television industry, where he and Camilla, who attended for part of the event, chatted with a host of famous faces including actors Damian Lewis, Emily Mortimer and Lucien Laviscount, and Gladiator director Ridley Scott.
Gun salutes will be fired in Green Park by The King's Troop Royal Horse Artillery and at the Tower of London as part of the military's traditional celebrations on the sovereign's birthday, and bells will be rung at Westminster Abbey where the King was crowned in 2023.
Charles, like his late mother Elizabeth II, has two birthdays, his actual one on November 14, and his official one, which falls on the second Saturday in June.
Since 1748, the monarch's official birthday has been marked by the parade known as Trooping the Colour, which was usually held on the king or queen's actual birthday.
