"In the mid 1960s, thanks to a convergence of music, film, fashion and social change, the mod look blasted out of London, with the boutiques of Kings Road and Carnaby Street at the epicentre of the scene.
For the first time in history young people had other options than to dress like their parents. Up until then clothes for young women were known as Juniors or Misses – a watered down version of adult clothes.
The sixties changed all that when young people started making the clothes they wanted to wear, clothes that completely excluded their parents’ generation. The mod look was about looking forward to the future: sharp, bold, minimalist – mod-ernist".

 The Shift dress was born around the same time as BIBA, I had a little look into the shift dress because it was sold at BIBA.

http://www.op-art.co.uk/op-art-fashion/