Caroline Hirons is a skincare guru and is described as the most powerful woman in the beauty industry. She started off on the shop floor, working on beauty counters at Harvey Nichols. Now she's the CEO of her own brand, Skin Rocks. She took the internet by storm after launching her blog over ten years ago, which has now been viewed more than 125 million times. That led to a Sunday Times bestselling book, which became the bestselling beauty book of all time.