The Duchess of Cambridge's sparkling sapphire engagement ring is one of her most famous pieces of jewellery.
She was presented with the gorgeous ring in 2010 when Prince William popped the question and she has worn it ever since.
The ring once belonged to William's late mother Princess Diana and features a 12-carat oval blue sapphire surrounded by fourteen solitaire diamonds.
But it was reported that shortly before her wedding in April 2011, Kate actually had the ring altered as she found the band was too big and "turning on her finger".
It is thought the ring was taken to royal jewellers G Collins and Sons, who made the tweak so it would fit better.
However, rather than resizing the band, small platinum beads are believed to have been attached inside the bottom of the ring, to give it a better fit.
A source told The Sun at the time that Kate 'adores' the ring, but found it had been too big.
The source added: "A bride's worst nightmare is looking down and seeing her ring has fallen off.
Love the royals? Sign up for the Mirror's daily newsletter to get all the latest news on the Queen, Charles, Kate, Wills, Meghan, Harry and the rest of The Firm. Click here to sign up.
"One can only imagine how this is magnified when you are marrying the future King of England."
Kate now wears the ring alongside her beautiful wedding ring, which is made from Welsh gold.
However, according to a documentary, Kate almost nearly didn't get her late mother-in-law's ring.
That's because it is believed the gorgeous piece of jewellery previously belonged to Prince Harry.
In the programme, The Diana Story, Diana's former butler Paul Burrell told how Harry "selflessly" gave up the ring, so his brother William could give it to his then-fiancee when he proposed.
He said that after Diana died following a car crash in Paris in 1997, Prince Charles allowed his sons to select pieces from her jewellery collection to keep.
It's believed the sapphire ring went to Harry, while William chose a gold Cartier watch.
But in the programme, Burrell explained that shortly before William proposed to his now-wife Kate in 2010, Harry offered his brother the chance to give his bride-to-be their mother's ring.
