Prince Harry designed Meghan's ring with Diana's diamonds

Prince Harry designed his fiancee Meghan Markle's engagement ring with a diamond from Botswana flanked with two diamonds from his late mother Princess Diana's personal collection. Photo / Getty

After 16 months of dating and increasingly fervent speculation, Prince Harry and Meghan Markle finally confirmed this morning what we'd all suspected - that they are engaged to be married. One of the first questions - along with "when?" - is "what's the ring like?", and at the photocall at Kensington Palace the couple offered us a first glimpse.

Set in yellow gold, the engagement ring features three diamonds, which carry special significance for the couple. The central stone is a diamond from Botswana: a country that Prince Harry has visited many times over his life, and where the couple have spent time together.

Flanking this are two further diamonds which come from the personal collection of the Prince's late mother, Diana, Princess of Wales. The ring was made by court jewellers Cleave and Company and designed by Prince Harry himself - a daunting task for any groom-to-be.

That Harry commissioned the ring himself suggests that the proposal has been a while in the making: typically bespoke engagement ring commissions take between six and eight weeks to come to fruition.

In this way the Prince follows tradition: it's customary for royal engagement rings to be custom-made, which is why Princess Diana caused some controversy when she chose her Garrard sapphire-and-diamond engagement ring from the shop's stock.

That ring might well have ended up on Meghan Markle's finger: when Diana passed away, her two sons each chose a piece of her jewellery.

Harry chose the ring, while William chose her Cartier watch. They later swapped, and William gave the ring to Kate Middleton when he proposed, saying it was a way to ensure his mother was a part of their wedding day.

In dismantling a piece of Diana's jewellery and using the diamonds, Prince Harry has also paid tribute to his mother in his choice of engagement ring.

But rather than keeping them as a heirloom, he has chosen to incorporate them into a new design, pairing them with a stone that has personal significance to him and Markle: a statement about the independence they plan to maintain as a married couple, perhaps?

Certainly, the pared-back, yellow-gold ring suits Markle's personal style far better than a vintage style would. It's modern yet timeless, and will complement her everyday wardrobe of shirts and jeans just as well as any black-tie gowns.

It appears to fit the bride-to-be perfectly, although of course it's not known exactly when Harry gave it to her, and it's likely that she will have had it resized.

Three-stone engagement rings are a popular choice (and likely to become all the more so, after this announcement), with the three diamonds said to represent friendship, love and fidelity, as well as the couple's past, present and future.

"From the very small picture I could see, it looks like a very rounded cushion-cut (square cut with rounded corners) stone of at least two carats, flanked by two brilliant-cut shoulder stones," says Vanity Fair's jewellery editor, and the Telegraph's jewellery expert, Annabel Davidson.

"From the Rappaport diamond pricing index a ring like this would cost at least £50,000 to buy new including the side stones - although there's no way to know what colour grade the central diamond is, which would hugely affect the price."