It is thought that Anna Wintour was the inspiration behind the demanding editor , Miranda Priestly , in the novel The Devil Wears Prada . The author of the book , Lauren Weisberger , had worked as the personal assistant of Anna Wintour at Vogue . Lauren Weisberger , a former Wintour assistant who left Vogue for Departures along with Richard Story , wrote The Devil Wears Prada after a writing workshop he suggested she take .