The discovery that one of the great icons of British costume and British royal history never belonged to King Charles at all, let alone ascended the scaffold with him, was made all of eight years ago by costume experts at the Victoria and Albert Museum.
But officials at Windsor Castle in effect hushed it up. The shirt is still in a display case in the royal library and the Queen regularly takes private guests into the room to see it. It is understood that the Queen has never been told the shirt is likely to be a fake.
Members of the Queen's staff are not allowed to be quoted by name; but one said: "I was here when the V and A costume experts said it was a lady's nightie and I turned a deaf ear to it. I am retaining my faith and belief in it. I still tell people this is the shirt that Charles I wore to his execution."
Another said: "Frankly, I suspect that it wasn't King Charles's shirt and the stains that look like blood are probably due to excessive ironing. But I don't believe in dismantling legends."
The shirt, acquired by Windsor Castle in 1911, is in a display case on which are written the words: "Shirt Worn by King Charles I at His Execution. Linen Shirt with Drawn Threadwork Borders. 17th Century."
Below, is a description: "This shirt traditionally held to be the second or over-shirt worn by King Charles I on the day of his execution (30 January 1649)." Sir Thomas Herbert, Gentleman of the Bedchamber to the King in his last two years, wrote in his memoirs of the King's request: `Let me have a shirt on more than ordinary by reason the season is so sharp as probably may make mee shake, which some Observors will imagin' proceeds from fear. I will have no such Imputation, I fear not death!'"
Perhaps significantly, the shirt is not being included in an exhibition in the Queen's Gallery in Buckingham Palace next January to mark the 350th anniversary of the execution. The exhibition will include paintings, prints and drawings of Charles as well as coins and medals.
One of the curators said that officially the shirt was not included because the exhibition was about portraits, but agreed that doubts about its provenance were also a problem.