The King’s coronation falls on the birthday of the Duke and Duchess of Sussex’s son Archie.
Archie, Charles’ grandson, turns four on Saturday May 6 next year, when the King will be crowned amid great pageantry in Westminster Abbey.
It has not yet been confirmed who will attend the ceremony and whether or not Harry and Meghan will be among those invited, or whether they will be able to attend since it will be their eldest child’s birthday.
More than 2,000 people are set to fill the Abbey to see both Charles and Harry’s stepmother, the Queen Consort, being crowned.
Buckingham Palace said the date of May 6 was chosen in consultation with the Government, the Church of England and the Royal Household, but no further details have been given on why it was picked.
It has not yet been confirmed whether or not there will be an extra bank holiday to mark the occasion – a matter which is decided on by the Government.
Harry has faced difficult times in his relationship with his father, telling US talk show host Oprah Winfrey he felt “really let down” by Charles, who had stopped taking his calls in the run up to the Megxit crisis, and how there was a “lot of hurt”.
The duke later lambasted Charles’s skills as father, criticising him for expecting his sons to endure the pressures of royal life, and suggesting his parenting left him with “genetic pain and suffering”.
Meghan told Oprah that Archie was not given the title of prince because of his race.
However, when Archie was born seventh in line to the throne in May 2019, he was too far down the line of succession to receive the title.
The duchess also accused an unnamed member of the royal family of making a racist remark about Archie’s skin tone before he was born.
Charles’s accession to the throne means Archie, who lives in California with Harry and Meghan and his one-year-old sister Lilibet, is technically now a prince.
But it has not been confirmed by the Duke and Duchess of Sussex or Buckingham Palace whether he will use the title of prince or whether Lili will use that of princess.
May 6 was also the wedding anniversary of the late Queen’s sister, Princess Margaret, who married in 1960. Margaret divorced her husband, the Earl of Snowdon, in 1978.
The King’s grandfather, George VI, had his coronation on May 12 1937.
The ceremony also featured the crowning of Charles’ beloved grandmother Queen Elizabeth, later known as the Queen Mother.
Other famous birthdays on May 6 include former prime minister Sir Tony Blair and actor George Clooney.
Other anniversaries include the death of Charles’s great-great grandfather King Edward VII – Queen Victoria’s son – on May 6 in 1910.
In 1954 on May 6, Roger Bannister ran the first sub-four-minute mile on the Iffley Road track in Oxford, in three minutes 59.4 seconds.
In 1994, the Queen and France’s then president Francois Mitterrand opened the Channel Tunnel, and Nelson Mandela and the ANC were confirmed as the winners in South Africa’s first post-apartheid election.
In 1997, the Bank of England was given independence from political control, the most significant change in the bank’s 300-year history.
It is also the anniversary of the birth of the founder of psychoanalysis, Sigmund Freud, in 1856, and of Italian silent screen heartthrob Rudolph Valentino in 1895.
