Kate Middleton Wears Diana's Engagement Ring But It Actually Belongs To Prince Harry

So why isn't it on Meghan Markle's finger?

Here's a twist we didn't see coming. Kate Middleton's whopping 12-carat sapphire engagement ring -- which she was given by her now-hubby Prince William -- wasn't Will's to give in the first place.

'Cause it actually belonged to his younger brother, Harry.

The stunning bling was once worn by his late mum, Princess Diana, and Harry inherited it after her death in 1997, according to the Amazon Prime documentary The Diana Story.

Image: Getty.

After their mother was killed in a tragic car accident in Paris, the two Princes -- then aged 15 and 12 -- were left three quarters of her $36 million estate (the other quarter was split between her 17 godchildren.)

When it came to her jewels, the late Princess instructed in a special "letter of wishes" that they eventually go to her sons' future wives, although she left it to the boys to chose who took what.

"I would like you to allocate all my jewellery to the share to be held by my sons, so that their wives may, in due course, have it or use it," the letter read.

"I leave the exact division of the jewellery to your discretion."

According to Diana’s former butler Paul Burrell, Will picked Diana’s Cartier watch, a 21st birthday gift, while Harry selected the ring his father gave her upon their engagement in 1981.

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The ring, a band of white gold featuring a 12-carat sapphire surrounded by 14 solitaire diamonds, holds special memories for Harry, Burrell revealed.

"I remember when I held mummy's hand when I was a small boy and that ring always hurt me because it was so big," the butler recalled Harry once saying.

So if the Haz inherited the rock from his late mother's collection, why is his sister-in-law wearing it now?

Image: Getty.

Or more to the point -- why isn't it on Harry's now-wife Meghan Markle's finger?

The answer to that is really rather sweet. Will was the first of the royal siblings to get engaged, popping the question to his long-time GF Kate in 2010. Of course that doesn't mean he automatically had rights over his mother's ring.

Instead it was Harry who offered it up -- once again, according to butler Burrell.

"Harry said to [Will]: 'Wouldn't it be fitting if [Kate] had mummy’s ring? Then one day that ring will be sat on the throne of England.'"

After their father Prince Charles, William is second in line to the British throne, meaning there's a high probability that both he and his wife the Duchess of Cambridge will wear the crown(s), so to speak.

Harry, on the other hand, is sixth in line, and dropping further and further back as Kate and Will continue to have kids.

In a show of love and respect for both his brother (and his lady-love) and their mother, Harry handed over what might've been one of his strongest connections to Diana.

Image: Getty.

Um, if that ain't brotherly love we don't know what is.

It all turned out more than okay in the end, however, as Harry was still able to gift his fiancé -- the now Duchess of Sussex -- an equally as beautiful and meaningful ring when he proposed seven years later.

The Prince designed the ring he gave Meghan Markle himself, which allowed him to make it extra special.

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The biggest diamond in the yellow gold band is from Botswana, where the couple escaped on a romantic getaway during their blossoming relationship.

The ring is also studded with diamonds from Diana's collection, so there's always a reminder of his beloved mum on his wife's hand.

The rest of Diana's jewels -- who owns what?

Asprey ring

Image: Getty.

The large aquamarine gem was worn by Princess Diana at a private viewing of the Christie’s auction of her dresses in 1997.

A year earlier on a trip to Sydney the Princess paired the ring with the matching bracelet, featuring a larger emerald-cut aquamarine nestled between six rows of pearls.

It's thought that Harry gifted the bling to Meghan, who wore it with her second gown on their wedding day before the two departed for their reception.

Image: Getty.

The Saudi Suite

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The Saudi Sapphire Suite -- which includes a watch, earrings, a bracelet, ring and diamond necklace -- was gifted to Diana as a wedding present from Saudi Crown Prince Fahd.

Kate now wears the earrings -- a gift from Will shortly after their engagement-- but made them her own by turning the studs into a drop style.

Image: Getty.

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The butterfly earrings

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Diana sported the gold and gem butterfly stud earrings during a visit to Canada in 1986, then over 30 years later her daughter-in-law did the same.

This time the dainty earrings made an appearance on Meghan Markle on day one of the royal tour in Sydney in 2018.

The Duchess paired the butterflies with a bracelet -- gold with blue stones inset -- also from Diana's collection.

Image: Getty.

The Lover's Knot Tiara

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Her mother-in-law the Queen loaned Diana the Lover's Knot Tiara -- also known as the Queen Mary Lover's Knot Tiara -- for her wedding.

Diana opted to wear some bling from her own family -- the Spencer Tiara -- on the big day, but she was reportedly a big fan of the Lover's Knot.

The pearl and diamond piece went back into the Queen's collection after Diana's passing, but re-appeared decades later.

The Duchess of Cambridge first wore the tiara in 2015, and the stunning piece has been seen atop her perfectly coiffed hair at least once every year since.

Image: Getty.

Feature image: Getty.