The love that glows in Thomas Gainsborough’s portraits of his daughters Mary and Margaret has not faded in 260 years. It manifests itself as actual light, illuminating their young faces, in his first painting of them together. They are romping through a bit of wild nature in about 1756, when Mary was around six years old and her younger sister Margaret was five. As Margaret reaches out to touch a white butterfly, her sister holds her hand warily, holding her back. They themselves make the shape of a butterfly, two wings of one fragile entity. In the National Portrait Gallery’s moving encounter with an 18th-century family, you see that butterfly grow, and see it broken.
The story of Margaret and Mary is like Jane Austen’s Sense and Sensibility, but with a tragic ending. Which is another way of saying it is a true story about women in the Georgian age. Yet it is not a sociological abstraction. It’s the intimate story of two sisters and their well-meaning father, and it has never before been told as clearly as by this lovely exhibition. The BBC should adapt it into a Sunday night drama. It’s got everything – frilly dresses, debonair youths, comic relatives – but instead of yet another posh house, it takes us into a world that’s joyously middle class.
Meet “Scheming Jack”, the reprobate uncle of Mary and Margaret. His black hair looks greasy and unkempt. He turns his eyes away shiftily. He’s got stubble on his chin. In an age of powdered wigs he’s not even trying to keep up appearances. Gainsborough was the youngest of five children, and this is his least successful brother: always hatching doomed schemes and borrowing from his brothers and sisters. Yet they weren’t posh, either. The artist’s sister, Sarah Dupont, looks strong-willed in a mass of white lace: she plainly has aspirations – yet her husband Philip was a humble carpenter. He’s unpretentious and contented in Gainsborough’s relaxed portrait of his brother-in-law.
Calling this show Gainsborough’s Family Album might suggest these portraits are modest. They are not. Gainsborough painted his family, for free, with the same brilliance he brought to the commissioned portraits of slave owners and countesses that made him wealthy. Born in Sudbury, Suffolk in 1727, the son of a failed provincial businessman – whom he portrays as a respectable gent – he would die, rich and famous, in his fine London home in 1788. Ever since, he has been slighted as a flatterer of the elite, by critics from William Blake to the Marxist John Berger, who caricatured Gainsborough as a simple celebrant of landed property.
By turning our eyes to the portraits he did for his own pleasure and satisfaction, this exhibition reveals the greatness of Gainsborough. The people here are so alive, it’s as if the gallery had got some actors to dress up and wander about – so incredible is the lightness and animation of Gainsborough’s brush. It’s not just art history that gets turned upside down but British social history itself. When he opened a studio in Bath, he hung up portraits of himself and his wife, Margaret, to impress customers: yet they are not fancy flatteries. Both are rawly real in spite of their finery. They are icons of a society that was mobile, individualist and modern.
Gainsborough’s most modern quality is his desire to be a feminist dad. Is that pushing it? In an age of profound gender inequality, his paintings reveal an intense and sustained belief in his daughters’ potential. Its most radical expression was his desire for them to become artists – and to be able to make a living from it. In one of his grandest portraits of them, done in 1763 to 1764, he shows them as art students. They both have their portfolios while they pose among the casts of classical statuary they’ve been copying. Yet here, just as in the earlier portrait of them chasing a butterfly, their different personalities emerge. Mary looks intently back at her father, sitting with her art materials on her lap, a calm and sombre girl. Margaret, standing behind her, gazes dreamily into space. The curators think she’s looking at a cast. To me her eyes don’t seem fixed on anything at all.
This was the start of the Romantic age, with its cult of “sensibility”, later mocked by Austen. Gainsborough’s portraits show Margaret becoming a woman of feeling. In a picture from about 1772 she looks up into the air, her expression ravished with poetic intensity. Gainsborough admires this in her because he himself was a closet Romantic who loved to paint dreamlike visions of the countryside. In his pastoral The Harvest Wagon, Mary and Margaret pose as rural labourers.
By around 1777, Margaret is rapt in music as she plays a cello-like cittern, her face expressing the power of the music. Mary, too, is a Romantic figure in an experimental, almost impressionist painting of her decked in flowers and blurry paint, a poetic beauty. But could Gainsborough’s supportive vision of his daughters as Romantic rebels really be fulfilled in an age when marriage was supposed to be the only career open to women?
In about 1774, he painted them together as aristocratic beauties, elevated, refined – and marriageable. It looks like surrender. Even Margaret keeps her eyes ahead and doesn’t daydream.
Margaret was to marry a musician. The marriage failed, and she would eventually go insane. Mary looked after her for decades. Yet in the paintings here they come alive, as complex, unpredictable human beings. So do their quirky relatives. And so does Gainsborough himself.
• At the National Portrait Gallery from 22 November until 3 February 2019.