Portrait of an Unknown Lady 1650-5 Joan Carlile circa 1606-1679 Presented by Tate Patrons 2016 http://www.tate.org.uk/art/work/T14495

Joan Carlile, “Portrait of an Unknown Lady” (1650–55) (Presented by Tate Patrons 2016, image via Tate/Creative Commons)

When a rare portrait by one of Britain’s first professional female artists went up for sale two years ago, auctioneers assumed it was the work of a man.

Depressing, but perhaps they couldn’t be blamed: the painting, “Portrait of an Unknown Lady,” dates to the mid-17th century, when it was practically unheard of for a woman to work as a professional artist. Women weren’t accepted into art academies until the mid-19th century, and it was hard for them to access art education elsewhere, especially without their husbands’ permission. Joan Carlile — eventually identified by a TV art historian as the portrait’s true author — was an anomaly.

Now, as part of a continuing effort to better represent women artists in its collections, Tate Britain has acquired “Portrait of an Unknown Lady,” depicting a woman in pearls and a white satin gown. Painted by Carlile in oil between 1650 and 1655, it’s the museum’s earliest work by a British female artist.

One of the painting’s previous owners, C.J. Douglas, attributed it to the Flemish Baroque artist Anthony Van Dyck when he sold it at Christie’s in 1927. It wasn’t recognized as one of Carlile’s few surviving works until 2014, when the TV art historian and dealer Bendor Grosvenor saw the painting listed in a catalogue for a Woolley & Wallis auction in Salisbury.

“When it was listed for auction the painting was thought to have been by a bloke,” Grosvenor told the Telegraph, “but I recognized it as Carlile’s from the sale notice as her style is quite recognizable if you know what it looks like.” Grosvenor purchased the work in December 2014 for£4,200 (~$5,452). Tate acquired the portrait from Grosvenor for £35,000 (~$45,438), and it will go on display next April.

Carlile, the daughter of one of the first keepers of the Royal Parks, worked in Covent Gardens, London’s artistic hotspot, painting portraits and reproducing works of Italian masters in miniature. A list of noteworthy English artists published in 1658 records Carlile as preeminent among only four women oil painters. Only 10 of her portraits survive, including paintings of Sir Thomas Browne and Lady Dorothy Browne, held at London’s National Portrait Gallery.

Despite Carlile’s accomplishments, her work was unrepresented in the Tate until now. “It’s a built-in prejudice,” Tabitha Barber, a curator of British Art at Tate, told BBC of the relative lack of painting by women in its historic collection. “You begin to think that great artists are male artists.” To correct the bias, “we have a big strategy in trying to make women more visible on our walls.”

Carey Dunne is a Brooklyn-based writer covering arts and culture. Her work has appeared in The Guardian, The Baffler, The Village Voice, and elsewhere.