Michael Dorausch from Venice, USA · CC BY-SA 2.0

Born Marie Louise Hartman, Hartley built a decades-long career as a performer and became one of the industry's most visible advocates for sex education, speaking and writing on female sexuality with a directness that made her, in the words of one profile, an "outspoken feminist" and "advocate for sexual freedom". By 2017 she had appeared in more than a thousand films, a body of work she has used as a platform to argue publicly for frank, shame-free sex education.