She's one of our most successful entrepreneurs, and a role model for business people everywhere.
Her latest book In the Arena is out now.
So why did Diane Foreman decide to write it?
"At the end of the day, it wasn't about money – it's about leaving the ladder down," she says.
"I wanted a book where particularly women, but men too, who want to grow good businesses could go 'yeah, I'll look at that and I'll see what she did wrong and what she did right'."
There's a lot of her life in the book, which she calls a "toolkit for entrepreneurs".
Watch the video for the full interview.