Since it was first built more than 85 years ago, almost every member of the Royal Family has learnt to swim in the Buckingham Palace pool.
It even survived a Second World War bomb.
But that has not stopped King Charles moving with the Times and deciding to turn down the thermostat – to help save money during the fuel price crisis, but also in keeping with his attempts to be environmentally conscious.
There have been surprisingly few photographs taken of the pool, ensuring that it remains a suitably private place of leisure for the Royals.
An aerial photograph of Buckingham Palace pinpointing the swimming pool on the grounds
Princess Elizabeth and Princess Margaret on the grounds of Windsor Castle on July 8, 1946
In the summer of 1938 architect James Jack Roberts drew up plans for a swimming bath to be built inside of the Palace’s north-west pavilion, and by spring 1939, the pool was completed.
‘When Princess Elizabeth and Princess Margaret Rose returned to Buckingham Palace with King George VI and Queen Elizabeth from Balmoral recently, they found a big surprise awaiting them in the Palace grounds,’ read one newspaper article, dated January 14, 1939.
The report added: ‘The surprise was a new swimming pool, which was specially constructed for the two little princesses so they may have their weekly swimming lessons next year at their own home.’
At the time of the pool’s construction, Princess Elizabeth was already described as a ‘fine swimmer’ and had recently passed a life-saving test with honours.
‘The then Princess Elizabeth showed no fear of the water either in swimming or diving and went on to an advanced level, winning a silver medal for life-saving when she was still a very young girl,’ Brian Hoey said in his book, Not In Front of the Corgis: Secrets Of Life Behind The Royal Curtains.
Both she and Margaret swam together almost every weekend during the summer months and had races and games together in their other pool at Royal Lodge, Windsor Great Park.
But the young princesses had almost no time to enjoy their gift before World War II broke out.
On September 10, 1940, a year after the pool was completed, Buckingham Palace was hit and it was damaged during the Blitz by a delayed-action bomb.
The pool was rebuilt after the war and a new generation of royals learnt to swim at Buckingham Palace, including the Queen’s four children, Prince Charles, Princess Anne, Prince Andrew and Prince Edward.
A view of the gardens at Buckingham Palace where the swimming baths can also be seen
King George VI and Queen Elizabeth inspecting the damage done to Buckingham Palace when a time bomb, dropped by a German raider, went off inside the grounds in September 1940
The front page of The Sun newspaper back in 1940 when Buckingham Palace was bombed
It was also reported that Prince Philip swam in the lavish bath pool every day.
During his childhood, an eight-year-old Prince Charles decided it was also the perfect spot for sailing his model boats.
His classmate, Richard Alston, told the Daily Mail: ‘We all made small model boats in woodwork and Charles invited us to the swimming pool at Buckingham Palace to sail them. As we went to launch ours, he brought out his replica of the Britannia. Life was not fair at times.’
Years later, Princess Diana regularly used the pool, leaving home at 7am and driving from Kensington Palace to Buckingham Palace for a round of swimming laps.
In happier times, both the then Prince Charles and Princess Diana splashed about in the pool and taught William and Harry to swim.
Charles revealed later that he had instilled a love of water in his eldest son from an early age.
‘I threw him in the swimming pool on occasions,’ he said. ‘Instead of putting him off, it enthused him.’
A photograph of the Queen, then Princess Elizabeth, aged 13, who had won the Challenge Shield in the Children’s Annual Swimming Meeting at the London Bath Club in 1939
King George VI, Princess Elizabeth and Princess Margaret collecting water from a swimming pool at the Royal Lodge in Windsor Castle in April 1942
However, it is now Prince William’s children, Prince George, Princess Charlotte and Prince Louis who enjoy the most exclusive pool in Britain.
The Mail revealed back in 2014 that Kate Middleton has been taking the then one-year-old George for swimming lessons in the private pool at Buckingham Palace.
Nowadays, King Charles has turned down the thermostat for the swimming pool at Buckingham Palace to help reduce the royal household’s energy use.
A source said: ‘A few people using the pool have noticed that the temperature has dropped. They have been told the King has had the heating turned down.’
A source who knows the King well told the Sunday Times that Charles probably thinks the pool, ‘is environmentally unsound because the water has chemicals and has to be heated.
‘It doesn’t fit with his exercise regime or his worldview.’
Royal fans may be surprised to discover that it isn’t just the Royal Family who enjoy the privilege of swimming there. According to royal author Brian Hoey, members of the Staff Sports Club can use the pool at ‘certain specified times’.
‘The rule is that if a staff member is swimming and one of the Royals appears, they have to get out, unless invited to remain, which often happens,’ Hoey wrote.
‘If when the staff member turns up a Royal is already in the pool, the servant, and this includes senior members such as the Private Secretary or Keeper of the Privy Purse, will not attempt to join them.’