This look was popularized by Yves Saint Laurent in the 1960s. He drew his inspiration from Paris streetwear: leather, turtlenecks, and short skirts, all in black. Saint Laurent broke from tradition and caused a stir with his new look. His commitment to have women be a part of the change as opposed to be a product of change was more than the House of Dior could bear. Saint Laurent soon departed Dior to create fashion under his own label.
Historical Dictionary of the Fashion Industry. Francesca Sterlacci and Joanne Arbuckle.