The story behind the pearl necklace which the Duchess of Cambridge borrowed from The Queen last night

Despite having access to one of the world’s most extensive jewellery collections, the Duchess of Cambridge has been relatively restrained when it comes to borrowing royal jewels. But a special occasion calls for a special accessory, and at last night’s dinner to celebrate the Queen and Prince Philip’s 70th wedding anniversary, the Duchess wore a four-strand pearl choker belonging to the Queen.

Paired with a black lace Diane von Furstenberg gown, the choker added a vintage touch to the Duchess’s look, while calling to mind her husband’s late mother, Princess Diana, who was renowned for her love of pearls. It comes as no surprise then to learn that Diana once borrowed that same necklace, wearing it to a state banquet in 1982 (incidentally, the year Catherine was born).

The choker was originally commissioned by the Queen using cultured pearls that were a gift from the Japanese government, and she wore it regularly in the 1980s and 1990s. The four strands of pearls are fastened with a diamond clasp, which on Her Majesty and Princess Diana sat at the base of the throat, but on the Duchess can be seen resting a little lower, on the clavicle.

Following in the Queen and Princess of Wales’ footsteps, the Duchess also paired the choker with pearl earrings. She wore a pair of Collingwood pearl and diamond earrings that had been given to Diana as a wedding present and appear now to have been passed on to the Duchess, who previously wore them in July at a state banquet for visiting Spanish royals.

The Duchess of Cambridge's best jewellery moments

Like her late mother-in-law, the Duchess has a penchant for pearls. This July she was photographed wearing a three-strand pearl and diamond bracelet that also belonged to Princess Diana, while pearl earrings by Annoushka and Kiki McDonough are a trusty part of her everyday jewellery wardrobe.

However unlike Diana, who was known for her bold and sometimes daring jewellery choices - she owned a number of chokers and memorably wore them as headbands - the Duchess of Cambridge has a more reserved approach, usually accessorising with a pair of statement earrings if the occasion calls for it.

Princess Diana's jewellery

Last night’s reception at Windsor Castle is one of a handful of occasions on which she has worn royal jewels. These include the Lover’s Knot tiara she has twice worn at Diplomatic receptions at Buckingham Palace, the Nizam of Hyderabad diamond necklace she wore at the 2014 National Portrait Gallery Gala, and, of course, the Cartier tiara lent to her on her wedding day.

This is the first time she has opted for a choker-style necklace and, given how many similar styles are in the Spencer family collection, it begs the question of whether she may continue the trend.

Her choice of accessory also pays tribute to the focus of the celebrations: Her Majesty the Queen, who can be seen wearing a three-strand pearl necklace in the official portrait released to mark her platinum wedding anniversary.

The Queen's most spectacular jewellery

The Queen also pairs her pearls with matching earrings, adding a pop of colour to her cream dress with a gold, diamond and carved ruby Scarab brooch by British jeweller Andrew Grima that was a gift from her husband in 1966. Such gifts aren’t always a guarantee of a marriage’s longevity, but judging by the couple’s united front 70 years on, they surely help.