Royal biographer Hugo Vickers believes the explanation is straightforward. Clarence House – found on The Mall, right next to St James’s Palace – simply feels more like a home. Writing in The Times, Mr Vickers argued that the property offers a far more comfortable living environment than Buckingham Palace, describing it as “the nearest thing to a country house in the capital”. By contrast, he painted a very different picture of Buckingham Palace, writing that it is “soulless” and more akin to “a large Edwardian hotel” than a place to enjoy everyday family life.

According to Mr Vickers, the King has deliberately preserved much of his grandmother’s influence throughout the house, retaining many of her paintings, furnishings and personal touches while commissioning only modest updates from the late interior designer Robert Kime.

The royal expert said he “never thought for one moment” that Charles would choose to leave Clarence House, particularly given its location just a short drive from Buckingham Palace. That means the King can continue living in familiar surroundings while using Buckingham Palace for its primary purpose as the monarchy’s ceremonial headquarters.

Mr Vickers also highlighted that Charles is not the first monarch to favour Clarence House over Buckingham Palace.

Following the death of King George VI in 1952, the future Queen Elizabeth II had hoped to remain at Clarence House, where she had lived with Prince Philip after their marriage. However, Mr Vickers wrote that then-Prime Minister Sir Winston Churchill insisted the new monarch should instead move into Buckingham Palace.

The move meant Clarence House became the home of the Queen Mother and Princess Margaret, with the Queen Mother remaining there until shortly before her death in 2002.

Today, Mr Vickers believes Charles’s decision makes “perfect sense”. Buckingham Palace will continue to host state banquets, investitures, garden parties and major royal occasions, while Clarence House provides the King and Queen with a more private base in central London.

“The King has been keen to open more rooms in royal residences to public view. It is possible to visit the balcony room at Buckingham Palace. He may well now give access to more private rooms at the Palace,” he wrote. “Staying on at Clarence House has many advantages and makes perfect sense.”