Barbara Hulanicki and Biba

If Mary Quant made young fashion, Biba made it affordable. That's the simplest way I can put it. Quant's clothes were revolutionary but not cheap; Biba sold the same excitement at prices a girl in her first job could actually manage, and in doing so became one of the most loved names in 1960s London.

Barbara Hulanicki was a fashion illustrator, and she started Biba with her husband, Stephen Fitz-Simon, as a small mail-order business. The breakthrough came in 1964, when the Daily Mirror offered readers a Biba pink gingham shift dress with a matching headscarf for a very low price. It far outstripped expectations, selling around 17,000. That showed there was a huge, underserved market of young women who wanted fashionable clothes and couldn't afford boutique prices, and Biba set out to serve it.

The first Biba shop opened later that year in a former chemist's on Abingdon Road in Kensington, then moved to bigger premises on Kensington Church Street and later Kensington High Street as it grew. The shops were unlike anything else. Instead of bright lights and neat rails, they were dark and atmospheric, with dark walls, Art Nouveau touches, loud music, and bentwood hat stands draped with clothes. Shoppers tried things on in shared changing rooms, and famous faces rubbed shoulders with teenagers. Stock turned over quickly, so you had to keep coming back.

The clothes had a look all of their own. Hulanicki used what she called "auntie" colours - plum, mulberry, rust, dusty pinks, and browns - in place of the bright primaries of mod fashion. Her dresses were tiny and narrow, with high armholes and long, tight sleeves, cut for a very slender, doll-like figure that suited the babydoll mood of the later decade. Towards the end of the 1960s, the look grew more romantic and nostalgic, drawing on the 1920s, 1930s, and Art Nouveau, and that's where Biba went next: in 1973 it took over a whole Kensington department store, known as Big Biba, before closing in 1975. For me, though, the 1960s shop is the heart of the story - the moment fashion stopped being something you saved up for and became something you popped in for on a Saturday.