How did a colour of mourning become the uniform of chic?

By being simple, accessible and rebranded. Black had meant different things before Chanel. In the early 16th century it signalled wealth among Spanish aristocrats and Dutch merchants, because black dye was very expensive. By the Victorian era it had become the colour of grief, with widows expected to wear it for at least a year, and of servants' livery.

Then, in 1926, American Vogue published a short, simple black dress by Coco Chanel, calf-length and straight, and called it 'Chanel's Ford'. Like the Model T, the little black dress was simple and accessible to women of all social classes, and Vogue predicted it would become a uniform for all women of taste. Chanel's designs, this one included, helped disassociate black from mourning and reinvent it as the uniform of the high-class, wealthy and chic. As Chanel put it: 'I imposed black; it's still going strong today, for black wipes out everything else around.'

Part of the trick was fabric. Chanel's early fashions used humble jersey, then mainly used for men's underwear, and she bought it mainly for its low cost, according to the Metropolitan Museum of Art. She boasted that she had enabled the non-wealthy to 'walk around like millionaires'.