Celebrations are in order for the royal family next week as the King turns 75 on Tuesday 14 November.
So, what will Charles be doing to mark such a milestone occasion?
The monarch's charitable causes will be at the heart of his celebrations.
On the eve of his birthday on Monday, the King will join fellow 75-year-olds for a special party at his countryside abode, Highgrove.
The monarch will gather at his Gloucestershire home on Monday with community champions who were, like him, born in 1948 as part of the generation of post-Second World War baby boomers.
The afternoon tea, featuring dancing with live music from a local rock choir, will also mark the 75th anniversaries of the NHS and the Windrush generation in 2023.
Then on Tuesday, the King and Queen will officially launch The Coronation Food Project.
Inspired by His Majesty, The Coronation Food Project seeks to bridge the gap between food waste and food need across all four nations of the United Kingdom, helping people and helping the planet.
Charles and Camilla will visit a surplus food distribution centre outside London, where they will have the opportunity to meet staff and volunteers, hearing about the ways food waste can be used for social good.
The King will also host a reception at Buckingham Palace on his birthday for 400 nurses and midwives, as part of this year's NHS 75 celebrations.
The NHS choir is set to perform a surprise birthday song in his honour.
His Majesty will also reportedly be joined by close family and friends for a private dinner at Clarence House on Tuesday evening.
All about King Charles
Charles Philip Arthur George was born on 14 November 1948 as the eldest child of the late Queen Elizabeth II and the late Duke of Edinburgh.
He became heir to the throne at just the age of three when his grandfather King George VI died and his mother Elizabeth II became monarch.
Charles was educated at Cheam School and Gordonstoun, and he later earned a history degree from the University of Cambridge.
He has served in both the Navy and the Royal Air Force.
In 1981, he married Lady Diana Spencer and the couple went on to welcome Prince William a year later and Prince Harry in 1984.
Charles and Diana's marriage broke down and the pair finalised their divorce in 1996.
Diana, Princess of Wales was tragically killed in a car crash in Paris in 1997.
In April 2005, Charles married his long-term partner, Camilla Parker-Bowles.
He became King following Queen Elizabeth II's death on 8 September 2022. At the age of 73, he became the oldest person to accede to the British throne, after having been the longest-serving heir apparent and Prince of Wales in British history.
Charles and Camilla's coronation took place at Westminster Abbey on 6 May 2023.
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