Queen Letizia channels Princess Diana and Margaret in plunging cocktail dress

Queen Letizia looked elegant in an ankle-grazing cocktail dress today which she teamed with her flowing brunette locks worn loosely over her shoulder.

Designed by Carolina Herrera, the $1,990 (£1,543) garment featured a black sweetheart neckline and a feminine a-line skirt adorned in a grey-scale watercolour print.

Grey, black and faint blue flowers were set on the bright white material and the full skirt was separated from the ruched bust with a simplistic black knotted bow at the waist.

The low-cut dress was unlike anything style icons like Kate, Princess of Wales has ever been seen wearing, though it did bear resemblance to gowns worn by the late Princesses Diana and Margaret.

Both left behind their own unique fashion legacy, in which cocktail dresses were a common staple.

The gown worn by the Spanish queen today featured many details loved by the former Princess of Wales, Diana.

One of which was the fuller a-line skirt which the first wife of King Charles donned on many occasions during her first few years as a member of the British Royal Family.

In 1981, a then 20-year-old Diana stepped out in a red chiffon Bellville Sassoon dress at the premiere of For Your Eyes Only.

Though it was very different to Letizia’s Carolina Herrera outfit in its pattern, the silhouette was largely the same.

Cut with a flattering sweetheart neckline and a lightly ruched bodice, the top of the dress bore a resemblance to the Spanish royal’s figure-hugging, low-cut outfit.

The full a-line skirt highlighted the definition of the waist, while feminine straps drew the eyes to Diana’s delicate collarbones, much like Letizia’s.

While the former Princess of Wales’s Belville Sassoon number was made with thin spaghetti straps, the thicker style used on the Carolina Herrera gown had the same effect on the overall shape of the Queen’s floral garment.

Both dresses were made with a tall skirt though Letizia’s cut off just at the ankles, unlike Diana’s floor-length hem.

The Spanish royal’s daring style is unlike anything worn by the likes of Princess Kate, Duchess Sophie and Queen Camilla, but the deep-cut neckline is something that was often styled by famed “rule breakers” like Diana and Princess Margaret.

In fact, some of Margaret’s most iconic looks include collarless, cocktail-inspired gowns. A notable style worn by the late Princess was a silk black cocktail dress embroidered with sequins and diamanté by Norman Hartnell.

The designer crafted the bespoke number for Princess Margaret around the time of her sister’s coronation as Queen Elizabeth II.

Made from heavy black ribbed silk called grosgrain, Norman designed it specifically for the Princess’s taste for clean lines and minimal decoration. In this case, only the shoulder straps are embroidered with silvered beads and diamantés, allowing the skirt to be the most important feature.

The unique look was incredibly similar to Letizia’s watercolour cocktail dress which featured the same sweetheart neckline, wide straps and full skirt to create an hourglass silhouette.