By 1895 the Industrial Revolution had filled Europe’s cities with coal smoke. The design world split in two: in Britain, William Morris’s circle looked to the ‘past’ (reviving medieval craft); on the continent, the young decided to look to ‘nature’ — plants, vines, waves, a woman’s long hair.

From the green ironwork of the Paris Métro entrances (Hector Guimard), to Mucha’s theatre posters for Sarah Bernhardt, to Klimt’s gilded embrace in Vienna, to the fairy-tale houses Gaudí coaxed out of Barcelona — their shared motto was ‘not a single line is straight.’

Art Nouveau lasted just 15 years — the moment World War I broke out, this ‘over-refined’ aesthetic looked instantly out of step. It became, in effect, an older draft of Art Deco; but its DNA of ‘organic natural curves’ survives to this day: Apple’s iOS icons, the Airbnb script logo, even every ‘wellness’ brand.