Some of Prince Philip's youngest relatives were able to pay tribute to their great-grandfather by attending his memorial service.
Among them were the Duke and Duchess of Cambridge's older children Prince George and Princess Charlotte.
However, their youngest child Prince Louis, aged three, stayed at home and did not join his parents and older siblings.
But royal fans have spotted a clue that Kate and William may have considered taking Louis with them.
On Twitter, Patricia Treble noted that the Court Circular, the official record of the Royal Family's activities, had included Prince Louis' name as attending the service - although it had TBC (to be confirmed) beside it.
She wrote: "Interesting nugget in the Court Circular, 'Prince Louis of Cambridge [TBC]'.
"Sure, he turns 4 next month but that would have been a long service for such a young boy."
It was also picked up on the account Gert's Royals, with one royal fan saying: "It's got TBC after Prince Louis so it possible he was going, but at the last minute plans changed."
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However, Gert's Royals wrote: "Prince Louis’s name was likely just an error. I don’t think he was ever scheduled to attend."
The Court Circular has now been updated to show that Louis did not attend - only George and Charlotte.
Even though he made his public debut on the steps of the Lindo Wing with his parents at just a few hours old, Louis, who is four later this month, has been growing up away from the spotlight.
It's partly down to the Covid-19 pandemic, which has seen large-scale Royal Family events such as Trooping the Colour, cancelled in recent years.
And this has also played a part in causing him to fail to hit one major royal milestone - going on an overseas tour.
Louis has yet to go on a royal tour, which is mainly due to the travel restrictions that were in place for large parts of 2020 and 2021.
Louis' older siblings George and Charlotte were both considerably younger than their little brother when they went on their first overseas tour.
George went on his first royal tour when he was just nine months old, visiting Australia and New Zealand with his proud parents.
Charlotte made her royal tour debut in 2016 when she joined the family on a visit to Canada at 16 months.
