New York turns fashion hub of the world for a week starting Thursday, as top designers do battle for the hearts and minds of millennials in a social-media whirlwind of models and celebrities.

US designer Tom Ford – fresh back from a stint in Paris – opened the extravaganza that is New York’s spring/summer fashion week on Wednesday evening.

Among the most hotly anticipated collections is Raf Simons’ second line for Calvin Klein, after an avant-garde show designed along with American artist Sterling Ruby last February.

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Considered one of the most talented designers of his generation, the 49-year-old Belgian joined Calvin Klein from Dior in 2016, embarking on a mission to overhaul the iconic New York brand, redesigning its logo and transforming its Madison Avenue flagship store.

Simons will be rubbing shoulders with some of the great names of American fashion, from Ralph Lauren to Marc Jacobs, as well as newcomers Matthew Adams Dolan or Snow Xue Gao.

But New York Fashion Week is still smarting from the loss of a string of designers who have taken their collections to Paris or Los Angeles.

Among the departees are Proenza Schouler and Joseph Altuzarra, who joined the likes of Tommy Hilfiger and Rodarte in leaving New York.

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“When a big name like Altuzarra announces he is leaving, it weakens New York as a creative hub a little more each time,” said Rene Celestin, founder of fashion show production group Obo.

He believes that while the fraught US political climate “does not help,” there are many reasons behind New York’s waning popularity – and none which cannot be solved.

‘Natural cycle’

Imran Amed, founder and editor-in-chief of London-based website Business of Fashion, has watched fellow fashion capitals London and Milan bounce back from their own low spells as part of what he calls a natural cycle.

“I don’t necessarily see it as part of a negative trend in New York. I just think it is a time of change,” Amed said, in a sector shaken up by new technology, changing customer behaviour, and an evolving fashion cycle.

“All of the executives are focused on something we are calling the generation gap, which is the millennial and new consumers which are going to account for about 45 per cent of the luxury goods industry by 2025.”

These younger generations, he says, expect a different kind of relationship with the brands they engage with, he added – a trend evident in the recent collaboration between Coach and singer Selena Gomez, or Burberry’s campaign featuring Chinese pop star Kris Wu.

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In another trend to watch in New York, more and more designers are embracing plus-size models, perhaps the most famous of whom – size 16 Ashley Graham – hit the catwalk for Michael Kors in February.

MICHAEL MICHAEL MICHAEL!!! Thank you for the opportunity and showing that beauty comes in many different forms!! #michaelkors #nyfw

A post shared by A S H L E Y G R A H A M (@theashleygraham) on Feb 15, 2017 at 5:53pm PST

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Graham, a star in her own right with five million Instagram followers, will be in the New York spotlight both on the podiums and as a guest at several galas, including the Fashion Media Awards – where reality star-turned-model Kendall Jenner is to be named “fashion icon of the decade”.

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A post shared by Kendall (@kendalljenner) on Sep 3, 2017 at 11:01am PDT

Critics have suggested the 21-year-old half-sister of Kim Kardashian is undeserving of the accolade – but there is little doubt she can generate that all-important social media buzz.

Also expected to cause a stir is Rihanna, whose Fenty collection, in collaboration with Puma, will be showcased on Sunday.

this is such a look #rihanna #badgalriri #fentyxpuma

A post shared by Rihanna (@rihelite) on Sep 5, 2017 at 9:20am PDT

And Jenner’s brother-in-law Kanye West will no doubt spark a reaction with his sixth collection for his fashion brand Yeezy – a show which has so far been shrouded in mystery.