The relentless march of Brand Beulah! Princess Beatrice owns TEN. (And there doesn't seem to be a royal woman who hasn't worn the British label...)

Beulah London dresses have been worn by Catherine, Princess of Wales, Sophie, Duchess of Edinburgh, Princess Beatrice, Princess Eugenie and Zara Tindall READ MORE: The designer dresses the Princess of Wales has in multiple colours - including her favourite frock in FOUR shades

A volunteer trip to India, where they witnessed the harsh reality of modern slavery, proved life-changing for the founders of Beulah London.

During a three-month stay in the slums of Delhi in 2009, Lady Natasha Rufus Isaacs and Lavinia Brennan taught crucial sewing skills to victims of sex trafficking.

Upon returning to the UK, they established their brand the following year, driven by a commitment to create new opportunities for these women - and they have upheld this mission ever since.

Unsurprisingly, Beulah London's unique and uplifting initiative has gained significant attention in royal fashion circles: Catherine, Princess of Wales, Sophie, Duchess of Edinburgh, Princess Beatrice, Princess Eugenie and Zara Tindall have all donned its graceful designs.

Even Amazon Prime's latest film, Red, White and Royal Blue, based on the Casey McQuiston novel, offers a nod to the brand.

The movie, which follows the romantic relationship between the son of a US president and a British prince, stars Ellie Bamber as Princess Beatrice, complete with her Beulah London wardrobe.

But Natasha is thrilled to see women, whether royalty or not, donning her label.

'We are always delighted to see anyone wearing our dresses! It is a real honour to see the Royal Family wearing Beulah and supporting smaller British businesses,' she told MailOnline.

Princess Beatrice brought some much-needed cheer to a drizzly afternoon in her crimson 'Christina' dress

Beulah London founders, Lady Natasha Rufus Isaacs (right) and Lavinia Brennan, are dedicated to empowering vulnerable women through the fashion industry

Beulah London is almost always guaranteed to be spotted at royal events, which have included Trooping the Colour, Royal Ascot and the Queen's National Service of Thanksgiving.

The most recent sighting occurred on Monday, when Princess Beatrice dined at at La Loma, part of the private club Oswald's, located in Mayfair.

She repeated her 'Ahana' dress in forest green, pairing it with lace court shoes. 

The sleek fit-and-flare silhouette is a firm favourite of Beatrice, owning it in four variations - along with six further designs.

A few weeks earlier, the royal stepped out wearing the label's bestselling 'Christina' dress at a Buckingham Palace Garden Party.

She brought some much-needed cheer to the drizzly afternoon in her charming crimson frock, featuring delicate buttons and a frilled high neck.

'She looked stunning and elegant, as always,' Natasha said.

And Beatrice isn't the only royal with a penchant for Beulah London's vivid hues - Sophie, Duchess of Edinburgh, and Sophie Winkleman are also enthusiasts.

During last year's Coronation celebrations, Sophie donned Beulah's 'Yahvi' dress in bright coral, marking one of her finest ensembles to date.

The wife of Prince Edward epitomised summer chic, while showcasing her free-spirited dance moves and singing along to Lionel Richie's hit tune 'All Night Long'.

Made from RWS certified wool, which aims to improve the welfare of sheep and the land they graze on, Sophie's dress was designed and crafted in London, supporting British manufacturing.

Sophie, Duchess of Edinburgh, rewore Beulah's bright coral 'Yahvi' dress in April

Sophie Winkleman (left) and Princess Beatrice (right) have both worn the brand's 'Ahana' dress

The royals have worn Beulah London dresses for a number of significant events. Pictured: Sophie, Duchess of Edinburgh, at Trooping the Colour 2023 (left) and Zara Tindall at Royal Ascot in 2020 (right)

Natasha and Lavinia share an unbreakable connection - their grandmothers were great friends and Natasha's father went to school with Lavinia's uncle.

The duo's shared Christian faith inspired the Hebrew name of their company, which fittingly signifies 'transition from darkness into light and freedom'.

They strive to design timeless garments with distinctive feminine silhouettes, showcasing craftsmanship from India.

Before launching in 2010, Natasha and Lavinia carefully sought out global Impact Partners that shared their objective.

'Our vision is to create sustainable, alternative employment for vulnerable women,' Natasha explained.

'Inspired by the beautiful colours of India, we work with local communities, utilising craft techniques, such as weaving and embroidery, which we incorporate into our collections each season.'

The duo collaborates with NGOs, social enterprises, fair trade co-operatives and small specialist manufacturers to employ artisans in India.

Incorporating these crafts into Beulah's collections provides sustainable livelihoods for previously trafficked women, who either already possess the skills, or to whom they provide the training and tools to develop new skills.

It is also worth noting that Beulah London donates 10 per cent of profits to charitable causes.

The Princess of Wales wore the Beulah London's 'Sonia' blouson sleeve dress to a charity polo match in 2023

Kate chose to wear the elegant 'Yahvi' dress in olive for a London engagement in 2019

The Princess looked radiant in Beulah's 'Calla' shirt dress, crafted from floral-printed silk

One step ahead: Queen Mary wore Beulah London's 'Ahana' dress a year before Kate Middleton showcased the design

Their most prominent client is undoubtedly Catherine, Princess of Wales, who has been seen in several dresses from the ethical brand.

Kate holds a close bond with Natasha, who has known Prince William since childhood due to their fathers' friendship.

One of the most memorable outfits worn by the royal featured the 'Ahana' frock in blush pink.

She sported the classic fit-and-flare dress, featuring a mandarin collar and belted waist, both in 2021 and 2023.

The brand's influence extends beyond UK borders, with Queen Mary of Denmark leading the trend.

Ahead of the curve, Mary wore the beloved 'Ahana' dress a year before Kate.

Both royals also own the 'Shalini' navy geo print shirt dress and the flattering 'Yahvi' dress in olive.

Mary stepped out in a geo print shirt dress in 2019; Kate copied the look in 2020

Queen Mary, who been vocal about her commitment to sustainability, wore a berry velvet Beulah London dress in 2022

Considering Queen Mary's commitment to sustainability - she is patron of the Global Fashion Agenda and the Copenhagen Fashion Summit - it's no surprise she is a fan of the London-based label.

Regarding what's in store for the brand, Natasha told us: 'We’ve just come back from a trip to India in March, where we visited Jaipur. We are always captivated by vibrant colours and textures, and draw inspiration from the local markets.'

Both founders successfully manage their independent label alongside family commitments, which they consider their greatest accomplishment.

'Running a business whilst bringing up small children has been a real challenge, but equally very rewarding!' Natasha explained.

'Our greatest achievement is to have kept going and persisting through the tough times.'