Massenet, a former Tatler journalist and ex-head of the British Fashion Council, set up Net-a-Porter in 2000 after finding it hard to source clothes for a photo shoot.
She used loans from friends and family to set up the webpage, which was designed so users could ‘click’ to buy items they liked, and turned it into a £1.45billion retail business.
Massenet is estimated to be worth £143million after the business was sold in 2015 to online Italian fashion giant Yoox Group.
She now runs her own fund – Imaginary Ventures – which has backed the seamless tights range Heist and Khloe Kardashian’s Good American jeans brand.