Princess Anne added a special detail to a key royal engagement on Tuesday to mark a key occasion following.

The Princess Royal hosted the 40th Annual Butler Trust Awards at St James’s Palace and had invited King Charles as a surprise guest at the event.

Anne, who was dressed in a forest green dress for the ceremony, seemed to lifting the monarch’s spirits after his much-anticipated trip to Italy was postponed due to Pope Francis’ health.

Anne marked the occasion with a sweet gesture as she broke out one of her favourite jewellery pieces – a gold and diamond brooch, shaped like a knotted ribbon.

The accessory has been in Anne’s jewellery box since at least 1969 and the Princess has worn it for several notable occasions over the years – including for her 70th birthday portraits in 2020, per The Court Jeweller, via Hello!

King Charles’ sister was first seen wearing the brooch when the royal family welcomed Apollo 8 mission Commander, Colonel Frank Borman, to Buckingham Palace in 1969.

Anne, who is the Patron of The Butler Trust since its creation in 1985 and champions their work in promoting excellence in UK prisons, probation and youth justice, was seen having a delightful interaction with her brother in photos shared by the Palace.

The brother and sister duo, who have always shared a close bond, appeared in good spirits during the event.