In "The Weaker Sex", which is dedicated "To my girl", the actor reveals intimate and graphic details about her childbirth in 2015, rails against the pressure on women to look pristine in the aftermath, and describes the deep love she feels towards her young daughter and mother.
"My vagina split," the first line reads. "You came out with your eyes open. Arms up in the air. Screaming. They put you on to me, covered in blood, vernix, your head misshapen from the birth canal. Pulsating, gasping, screaming."
The essay is included in a new collection published this week, Feminists Don't Wear Pink (And Other Lies), curated by the writer and cofounder of The Pink Protest, Scarlett Curtis. Featured alongside Knightley is a plethora of high-profile women in Hollywood, activism, the arts and business, including Emma Watson, Saoirse Ronan, Adwoa Aboah, Jameela Jamil and Whitney Wolfe Herd.
Knightley explains her first breastfeeding experience and the gory, visceral nature of labour with refreshing frankness, using the metaphor of a battleground to emphasise the strength of the female body. "You latched on to my breast immediately, hungrily, I remember the pain. The mouth clenched tight around my nipple, light sucking on and sucking out.
"I remember the shit, the vomit, the blood, the stitches. I remember my battleground. Your battleground and life pulsating. Surviving. And I am the weaker sex? You are?"
The day before the birth, she remembers feeling her waters break during a walk on London's Clerkenwell Road and the fluid running into her favourite shoes ("brown lace-up brogues", which ended up "crusted and sticky" with amniotic fluid). On the day, Knightley remembers the "blood soaking through the sanitary pad wedges between [her] legs" and "exposing [herself] to the men in the room, blood running down [her] thighs, arse, cellulite." She recalls drinking champagne and eating Chinese food.
Her daughter was born the day before Kate Middleton gave birth to Princess Charlotte on 2nd May 2015, she flags, before railing against the burden on high-profile new mothers to be camera-ready virtually immediately after labour. "We stand and watch the TV screen. She [Middleton] was out of hospital seven hours later with her face made up and high heels on. The face the world wants to see.
"Hide. Hide our pain, our bodies splitting, our breasts leaking, our hormones raging. Look beautiful. Look stylish, don't show your battleground, Kate. Seven hours after your fight with life and death, seven hours after your body breaks open, and bloody, screaming life comes out. Don't show. Don't tell. Stand there with your girl and be shot by a pack of male photographers."
Knightley also discusses the sexist double standard applied to male and female actors who happen to be parents. "I turn up on time, word perfect, with ideas and an opinion. I am up with you [her daughter] all night if you need me. Sometimes I cry I'm so tired. Up with you all night and work all day... My male colleagues can be late, can not know their lines. They can shout and scream and throw things. They can turn up drunk or not turn up at all. They don't see their children. They're working. They need to concentrate."
She describes the disrespectful and dismissive behaviour she has been subjected to on set at the hands of men. "I work with men. I watch them and they watch me. They worry that I don't like them. It drives them mad. They belittle me, they try not to listen to me, they don't talk to me, they don't want to hear my voice, my experience, my opinion.
"Be pretty. Stand there. Tell me what it is to be a woman. Be nice, be supportive, be pretty but not too pretty, be thin but not too thin, be sexy but not too sexy. Be successful but not too successful. Wear these clothes, look this way, buy this stuff.
"I work with men and they worry that I don't like them. It makes them mad, it makes them sad, it makes them shout and scream. I like them. But I don't want to flirt and mother them... I don't want to flirt with you because I don't want to fuck you, and I don't want to mother you because I am not your mother."
Feminists Don't Wear Pink (And Other Lies), curated by Scarlett Curtis, £12.99, is published by Penguin and available now.