Long before Kim Kardashian debuted a freshly chopped bob haircut late last week, and definitely before Hailey Baldwin, Jordyn Woods, and little sister Kylie Jenner lobbed it off a few months before that, it was Coco Chanel, Louise Brooks, and the OG trailblazer behind the bob hairstyle as we've come to know it, Irene Castle, who set the trend.