Lady Kitty Spencer was the image of elegance as she dazzled at the second annual British Museum Ball on Sunday.

The niece of Princess Diana stepped out in a striking ruched red satin gown and cape from Dolce & Gabbana for the occasion, which saw more than 850 glamorous attendees gather in London's historic British Museum. 

In line with the event's red dress code, Lady Kitty, 35, opted for a pair of Dolce & Gabbana red heels and an extravagant diamond choker from Chatila Jewellers. 

Lady Kitty styled her golden locks in an updo and showcased a soft make-up look with a pink-toned lip gloss as she posed alongside Emma Thynn, Marchioness of Bath.

A star-studded line-up from the arts, fashion, film and philanthropy gathered to celebrate three global milestones for the museum, including the historic loan of the Bayeux Tapestry from France.

Maya Jama and Mick Jagger were among the glamorous guests championing the importance of art and culture at the event, described as London's rival to the Met Gala.

For its second year, the theme of the landmark ball was red  – the earliest pigment known to have been used by humans in artistic expression. 

Avid royal fans noted that Lady Kitty's look strongly resembled her late aunt's signature red ensembles – with the late Princess of Wales opting for a similar gown at a Claridge's Banquet in July 1989. 

Diana's £400,000 scarlet dress, designed by Bruce Oldfield, caught the attention of onlookers around the globe, and was re-worn by the princess at the premiere of When Harry Met Sally that November. 

Maya Jama, 32, currently starring in Celebrity Traitors, swapped her green Traitor's cloak for a burgundy ball gown, which she teamed with a beaded choker necklace.

Emma Thynn, meanwhile, also adhered to the dress code, wowing in a scarlet red gown. The Marchioness of Bath, 40, showed off her long legs and matching heels with the gown's daring thigh-high split as she posed outside.

However, Mick Jagger, 83, and his partner, Melanie Hamrick, 39, deviated from the colour scheme – with Melanie selecting a golden dress and a dash of red lipstick. 

Lady Kitty's glamorous appearance at the British Museum Ball comes after she offered her social media followers a rare glimpse into the glamorous summer she's enjoyed with her millionaire businessman husband and their young daughter.

Taking to Instagram, Lady Kitty shared a heartwarming image of Athena, three – who she shares with British-South African investor Michael Lewis, 67 – dressed in a sweet cherry-print dress in the sunshine.

While clutching a baby doll and wearing a pair of white sandals, Athena walked along a beach with sunloungers visible in the distance.

It's been a summer of enviable travel for Lady Kitty, with jaunts to The Hamptons in New York and the French Riviera – onboard a superyacht, no less – all while the controversy surrounding her father Earl Spencer has swirled.

Lady Kitty has distanced herself from any of the drama surrounding her father, who recently published his explosive memoir Swan Song: Diana, My Sister.

Images posted on social media have shown her posing in a striking two-piece onboard the Maison Mytheresa's luxury superyacht – which sailed between Monaco and Saint-Tropez in June, long before the release of Charles Spencer's book last month.

The exclusive invite-only yacht offers bespoke suites and a large pool with eight cabins onboard at a staggering cost of approximately £509,000 per week.

In a catalogue of 20 enviable photographs and videos shared to her Instagram last month, Lady Kitty also posted a couple's photo with her rarely seen multimillionaire husband Michael, whom she wed in July 2021.

Lady Kitty, who is 32 years younger than her husband, also offered a glimpse into her private family life – including a picture of Athena enjoying the crystal-blue sea.

Showcasing her effortless style, Lady Kitty put on a glamorous display in a red and white-striped Silvia Tcherassi dress and soaked up the vibrant sunshine in a purple mini dress and sunglasses.

In other photographs, Lady Kitty and her daughter are seen snoozing on a yacht, enjoying a spot of tennis and playing in a water ring-toss game at a market in what appears to be a French town.

The pair were also seen roaming the grounds of a large waterside villa, while young Athena lay in a hammock against a picturesque sea backdrop.

Combined with family photographs, Lady Kitty also posed by the water with Carla Ballerio Greggio, creative director of interior design studio Sabrina Monte-Carlo.

To round off her luxurious summer travels, the socialite posted a video of singer Jennifer Lopez performing on stage – believed to have been filmed during the Dolce & Gabbana Alta Moda festivities in Sicily.

Lady Kitty has kept her relationship with Michael largely out of the public eye, rarely sharing photos of him on social media and choosing to step out solo for most red-carpet events.

The couple, who first met through mutual friends in 2018, tied the knot in a glamorous ceremony at a stunning Italian country mansion three years later. They secretly welcomed Athena in 2023 and only announced her arrival on Mother's Day the following year.

In August, Lady Kitty shared a glimpse of her trip to The Hamptons on Instagram – posting several images from the 'sweetest summertime' in the popular holiday spot often frequented by A-listers.

Lady Kitty oozed elegance as she posed in a glamorous floral maxi dress, which she paired with pink heels, during an intimate dinner hosted by fashion designers Carolina Herrera and Wes Gordon, and Sarah Wetenhall, founder of the boutique hotel Hedges Inn.

Elsewhere, Lady Kitty posed in a polka dot bikini top, while also showcasing her family time in the sun – including trips to the supermarket, footprints in the sand and Athena feeding farm animals.

Combined with family snapshots, Lady Kitty also shared a photograph with dermatologist Dr Macrene Alexiades at an event for nail varnish brand Essie, alongside footage of American DJ Diplo during a performance in The Hamptons.