Burberry, Dolce & Gabbana and DKNY have all attempted to crack one of the fastest-growing markets - Islamic fashion.
What started as brands targeting wealthy Muslims with one-off fashion lines for religious occasions, has grown to a global trend for women who prefer to dress conservatively.
According to the Pew Research Center, Muslims are the world's fastest-growing major religious group. By 2050, it estimates there will be 2.7 billion Muslims worldwide, making up 29.7 percent of the global population.
And when it comes to the Islamic or modest fashion sector, spending is forecast to grow five percent annually to $361bn by 2023.
Turkey is the biggest spender on modest fashion: $28bn a year. This is followed by the United Arab Emirates (UAE) and Indonesia. But it is not a one-size-fits-all-trend; what is popular in Indonesia may not have the same appeal in the Middle East.
"This is not a new thing, it's not a passing fancy. It's been around since the beginning of time and it will be until the end of time," says Alia Khan, chairwoman of the Islamic Fashion Design Council, talking about the rise of the Islamic fashion industry. "It's actually surprising that we didn't see a platform like this years ago."
She credits social media, and the presence of "Muslim fashionistas" and "modest social influencers", as having a lot to do with global fashion brands beginning to take notice.
"The opportunity has always been there. We've had a huge consumer market for a long time, primarily led by the Muslim global population ... It's indeed a coveted consumer. And finally, this consumer is being noticed and getting a nod from brands like D&G, DKNY, Victoria Beckham, Tommy Hilfiger - all of them now. Zara has come up with their own Ramadan collection."
"There is some due diligence required" in brands understanding this audience, Khan says. "It's a completely different mindset, it's a different audience, it's a different consumer behaviour. And if the brand can understand that, they will succeed."
According to Khan, some of the Ramadan collections that went out "didn't quite get the point and consumers spoke about that. There was a lot of chatter on social media where the fashionistas were feeling like they weren't represented correctly ... So there's certain guidelines that need to be respected. This is a lifelong journey for them ... if you do get this audience, you've got this consumer for life."
Some of those most keyed into the demands of consumers are, of course, young Muslim entrepreneurs; she points out: "The young Muslim designers and start-ups that are succeeding are doing so because they understand this market and perhaps they are the market as well."