In 1931 the journalist Robert de Beauplan wrote of “a town in France, where summers start at the beginning of spring and ends at the end of autumn… There, you can see women wearing strange dresses. It's strictly speaking Pyjamapolis." The town in question was Juan-les-Pins, a popular resort on the French Riviera also nicknamed ‘Pyjamaland’ where women were just as likely to be seen drifting across the sand in loose trousers as they were swimsuits.

These “strange dresses” were in fact beach pyjamas – though as de Beauplan went on to point out, this subcategory of clothing ranged from "the afternoon outfit, for visits, tea, dancing and cocktails” through to "night pyjamas” which also resembled gowns “from afar when you see them in casinos, until you see the person dance quickly the fox-trot and then, there's no mistaking."

In the 1920s and 30s, the Côte d’Azur became a place to see and be seen, attracting luminaries from across the creative sphere including Coco Chanel, Jean Cocteau, Pablo Picasso, Dora Maar, Zelda and F Scott Fitzgerald, and Ernest Hemingway. For many of the bright young things and bohemian creatives seeking sun, relaxation and creative opportunity, a new mode of dress emerged. One that was both easy and breezy. The beach pyjama took its inspiration from several sources, from naval uniforms (the Breton-striped mariniere is also an icon of Southern French style) to sportswear and sleepwear.

Often, though, it is Chanel who is credited with kickstarting their rise in popularity – her much-documented borrowing from the menswear department extending to beachwear too. A frequent visitor to the Riviera, Chanel was spotted as early as 1918 enjoy the sights in a loose shirt and pair of trousers. Where she wandered, others followed. By the mid-1920s the beach pyjama was a hot ticket item, and by 1931 the New York Times would be observing that they were “firmly entrenched in fashionable circles… last summer already saw them dining out in the casinos of Biarritz and Lido and this summer they are taken for granted in the smart resort wardrobe.” Chanel, of course, had begun designing them for sale too (when asked about her motivations, she said she’d been spurred on by wanting to provide an alternative to the unseemly sight of people lunching at the Venice Lido – another jet set hotspot – in damp swimwear). They were, one assumes, a frequent sight at her tastefully decorated villa La Pausa on Roquebrune-Cap-Martin.

The beach pyjama was an infinitely malleable garment, a blank canvas for the brightest colours and most eye-popping patterns, or the epitome of chic in crisply relaxed white. Sometimes a one-piece or overall-style garment, sometimes a set of mix and match tops and bottoms, it was the kind of garment that offered the best kind of glamour: that which was not fussy or time intensive, but that could be flung on without thinking and worn all day.

It was also as practical as it was sartorially popular, crafted from cooling fabrics like cotton, linen or silk, and saving the wearer’s skin from the ravages of sun and sand. However, as it developed, many pairs of beach pyjamas came with open-backed halter tops: capitalising on the growing trend for a golden tan. Post WWI, everything was shifting. Gender roles had been loosened and a taste for hedonism was in the air. New modes of holidaying were on the rise too – and a vacation was a great excuse for a new resort wardrobe, especially when it meant being able to push the boundaries of taste and respectability in a place that forwent work in favour of leisurely play.

However, despite their widespread appeal the beach pyjama still had a subversive edge – especially at a time when the presence of women in trousers away from the shoreline remained scandalous. Chanel herself was subject to the restrictive norms of the day, once being barred entry to into a casino while wearing beach pyjamas, with the proprietor Edouard Baudoin telling her that she was “living proof that one must not merely be dressed, but well dressed.” In nearby Monte Carlo, one woman was even briefly arrested for wearing them, in line with ancient laws about women not wearing men’s clothing.

The beach pyjama was later supplanted in popularity by the bikini, while the rise in slacks gave women more trouser options in their daily lives. Their bohemian spirit, however, lives on. The beach pyjama was the forerunner of the 1960s palazzo pant (so-named by editor Diana Vreeland after the Russian princess and designer Irene Galzitine’s matching silk tunics and tops) and continues to conjure an intoxicating image of decadence today. Once a daring subversion of fashion etiquette, proving that sometimes one had to dress down in order to really dress up, now it offers a heady combination of opulence, relaxation and free-spirited vivacity.

Olivia von Halle’s Autumn Winter 2023 Collection pays homage to the glory days of Pyjamaland in a series of silhouettes including the unfussy crêpe de chine Alabama and sumptuously crafted Casablanca – both ideal for concerted lazing beneath a striped parasol, walks along the sapphire coastline, or a long, leisurely lunch at the Hotel Belles Rives. Really though, any of Olivia von Halle’s pyjamas would do the trick. As Chanel proved, it’s about the attitude with which you wear them – especially when you’re heading for Pyjamapolis.