Princess Kate's most timeless dress has a heatwave-approved side split

If there's one dress that represents the Princess of Wales, it's this beautiful, navy blue, polka-dot frock by Alessandra Rich that she's worn on numerous occasions.

Elegant, classic, and above all, timeless, the dress is the ideal working royal choice - it's respectful yet still fun and fashionable. Kate first wore the standout style in 2018, for her father-in-law, King Charles' 70th birthday portrait. It appeared that she liked it so much that she wore it a few months later on a visit to Bletchley Park.

© Max Mumby/Indigo

The dress had such a fluid shape, and alongside the brand's signature preppy collar and cuff detailing was a secret, thigh-high split that onlookers got a glimpse of as she did a walkabout. A thigh-high cut is ideal for a heatwave; it exposes the leg, giving great airflow.

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Kate's 'most copied' dress

This dress was also worn by Suits actress Abigail Spencer at the wedding of the Duke and Duchess of Sussex in 2018, and what's more, a sky blue version was worn by Kate's sister Pippa Middleton to Prince Louis' christening, which also took place that year.

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The lowdown on Alessandra Rich

Alessandra Rich's namesake label was founded over 16 years ago, in 2010. The brand claims it "deliberately distances" itself from "conventional aesthetics," explaining it designs clothes for shoppers who "see fashion as both language and play." 

Speaking to The Telegraph in 2019, Alessandra explained how her creations focus on shape with a key forties-style ethos. She said: "These dresses are demure, they're covering the arms and legs, and they're in nice, fresh colours. But, there’s always a split somewhere, or a body chain underneath. It is both ladylike and naughty, and I think there is a bit of both in all of us."

One royal who embodied those two qualities of ladylike and naughty perfectly was the late Princess Diana, Kate's mother-in-law. Alessandra told the newspaper that Diana was, in fact, one of her muses. "She wore polka dots so well, and I know all of her looks by heart," she revealed.