“I felt terrible that I had bumped into this gorgeous blonde girl and apologised and then realised she had an Australian accent,” recalls Russo, who was working in London as a financial consultant. They chatted, exchanged phone numbers and began a long- distance romance after Ralph – who has a serious fashion pedigree – returned to Sydney.

A year later Russo sent her a one-way ticket to London.

Ralph’s grandmother was a couturier and her grandfather was a cordwainer (shoemaker). They built up their business in Sydney during the 1950s and ’60s. Her mother was a personal stylist and even her great-grandparents were in fashion.

Tucked away with a sewing machine, sketchpad and shared dreams in southwest London, the pair established their business in 2008. Within a few years they had moved to Sloane Street in Knightsbridge and to an atelier that soon outgrew the location as orders poured in, especially from the Middle East, where Sheikha Mozah (the wife of the former Emir of Qatar) and Princess Ameerah al-Taweel of Saudi Arabia became early clients.

In January 2014 they were invited to Paris by the Chambre Syndicale to present their collection during haute couture week.

Their clientele now includes the new global rich, daughters of Chinese billionaires, Middle Eastern princesses, Hollywood’s Angelina Jolie, who wore one of their suits to Buckingham Palace, and, from the fashion world, Natalie Massenet.

“Our clientele is so diverse: we have clients in nearly every single country in the world,” says Ralph.

It is often said that haute couture relies on about 400-500 wealthy individuals, but Russo says that is a misconception. “For us there are a lot more,” he says, pointing out emerging markets in Asia, for instance. “There is more wealth in the world than there ever has been and the number of ladies who can afford couture, who want couture, is far north of the numbers quoted.”

The Ralph & Russo atelier employs more than 200 (considerably more than Chanel or Dior), and has a clientele said to number 1,000. “The important thing for us, in couture especially, is to educate the customer.”

They have introduced some special couture pieces in their Harrods in-store boutique, where they introduce customers to the look and feel of haute couture craftsmanship.

“People in emerging markets have seen haute couture in the magazines and social media (Ralph & Russo has a 1.5 million following), but they have to book an appointment to come here or to another house in Paris,” says Russo. “However, through our retail experience we can have a few custom pieces to show them and they fall in love with the workmanship and design, and are converted.”

By retail, Russo is talking about the planned opening of 17 stand-alone boutiques around the world for their new ready-to-wear collection of romantic gowns and pared-back daywear (launching in October) and accessories, and to showcase some couture. They have clients in Hong Kong, China and Singapore, which are earmarked for boutiques in the next year or two.

They are shaking up the haute couture world, but that is not enough; this is about creating a Ralph & Russo universe. In contrast to the aloofness of the Paris houses, it is the accessibility to their craft and the easy-going pair’s approachability that has been winning them success.

“There were things planned that we had hoped to have launched, but haven’t yet,” Ralph admits with some regret. “We have a strong vision of what we want and we are putting a lot of love and effort into it.”