The Film Society of Lincoln Center recently screened a selection of films featuring the Anglo-French mother-daughter duo Jane Birkin and Charlotte Gainsbourg. Walking through a department store, a couple of years ago, I passed a selection of $500 jumpers designed by the daughter of another cultural dynasty, Bella Freud. They were emblazoned with curly, mock-handwritten embroidery referencing Jane, Charlotte, and Serge Gainsbourg, their ex-husband and father, respectively–“Je t’aime Jane”, “Gainsbourg is God”–a homage as well to Jane’s (arguably) most famous film appearance in Serge’s 1976 Je T’aime . . . Moi Non Plus.

I’d forgotten all of this iPhone-aided research by the time I watched Lars von Trier’s two-volume Nymphomaniac. The self-appointed film society of which I was a member at the time–population: 3–chose the film based on its hype on IMDb, and for its featuring the venerable Shia LaBoeuf. LaBoeuf had recently pulled a tooth out on film set for his art, and walked a red carpet event with a paper bag over his head for his art. And so we waited with bated breath to see where this scandalous film fit into his grand scheme of self-definition. But it wasn’t Shia LaBoeuf that we ended up talking about. Though the film’s title suggests grindhouse more than arthouse, Charlotte Gainsbourg’s performance as the self-diagnosed nymphomaniac at the film’s center is both vulnerable and ferocious, crushing the expectations of any movie-goer who assumes the film to be “sexy” even before von Trier’s clinical aesthetics do the same. The film certainly features sex scenes, but they aren’t there for the audience’s enjoyment or titillation. On the contrary, as the sex becomes increasingly extreme, Joe’s (Gainsbourg) struggle with a serious mental illness becomes more and more apparent.

Her performance is what makes the film important, even beyond the scope of von Trier’s usual provocations. Gainsbourg’s presence marks a subversion, perhaps even a violent inversion, of onscreen gender norms. Whilst the female characters in depictions of heterosexual intercourse are generally objectified, Joe’s sexual encounters are anything but light-hearted, and she participates in power struggles that go beyond obvious reversal–that is, simply objectifying the men. She is visibly detached and shows complete disregard, even contempt, for those that she selects as sexual partners. Even when she finds herself in a fairly domestic situation with Jerôme (LaBoeuf) and their newborn baby, she is unable to prioritize those relationships over her addiction. In this, the film breaks rules held more sacred than the dictates of the much-theorized male gaze. That a woman could, for any reason, choose a frequently dangerous sex life over her child and husband, and the maternal role which she is supposed to inherently pine for–without the requisite moral comeuppance to “teach her a lesson”–represents a complete violation of tradition. But even though Gainsbourg’s embodiment of these such notions may be revolutionary for cinema, they are far from groundbreaking for her family.

As a teenager, Gainsbourg starred alongside her mother in Agnès Varda’s 1988 film, Kung-Fu Master! (Le Petit Amour). Birkin appears as Mary-Jane, a middle-aged mother of two girls (both played by her real-life daughters), who falls in love with a fifteen year-old boy (Mathieu Demy). The film itself is not judgmental in tone; although it allows Lucy (Charlotte) to voice her disgust and anger when she eventually finds out about her mother’s secret affection, the scenes between Mary-Jane and the underage boy are tender enough to complicate that denunciation. One thing that is directly commented upon, however, is Mary-Jane’s role as a mother.

The very first time she appears in the film, she is cradling her youngest child in a shot almost Italian Renaissance-like in its meticulous composition, singing a French lullaby. This image of idyllic motherhood is infused into almost every moment in the film through Birkin’s presence. Whilst Gainsbourg’s role in Nymphomaniac revises generic depictions of female characters, using Joe’s aberrant sexuality in order to sever the traditional bond between woman and motherhood, Birkin’s role in Kung-Fu Master! is subversive in that her maternalism is not in conflict with her sexual narrative. Her motherhood is never at all threatened by any of the other feminized tropes that the film deals with, nor by her failures and flaws.

These are only two drops in the ocean of Gainsbourg and Birkin’s careers, but the stretch of time in which the two have remained culturally relevant, and the consistent quality of the films they choose to participate in, speaks to the significance of their cinematic contributions. In both Gainsbourg and Birkin’s films, female characters dismantle structures that are commonly criticized in feminist film theory, such as the male gaze, but often they go further, criticizing gender structures on an even deeper level which the audience may not have thought to question previously. For myself, their legacy is about fearlessness, both in the selection of their projects and in the construction of their characters. They are unafraid of the seemingly contradictory—soft-spoken, idyllic mothers who make very loud mistakes—and unafraid of material that will potentially shock or offend, without ever letting their performances become affected by that possibility.