50 years after her death, Marilyn Monroe's face is as familiar as it was in her heyday – that is not surprising, given that she was one of the most photographed women of her time. A classic American pin-up girl who became an acclaimed actress, she was known and admired the world over. The National Portrait Gallery's exhibition Marilyn Monroe: A British Love Affair showcases photographs and magazine covers from 1947 to 1962, taken by British photographers. Included in this selection are items from her famed 1956 visit to Britain, made together with her husband Arthur Miller, to film The Prince and the Showgirl. It is a small, simple exhibition – more of a display – but one which places some of the most famous photographs of Marilyn alongside less well-known ones.

There is very little publicity inside the National Portrait Gallery about this exhibition, and it takes some finding, but the giveaway comes as you descend the stairs to Room 33 – a large, bright monochrome photograph by Jack Cardiff of the siren Marilyn posing, hair swept loosely across her face. Relatively make-up free, she is almost unrecognisable, and it is perhaps telling of her state of mind that she later wrote to Cardiff, saying "Dearest Jack, if only I could be the way you created me". 

Through photographs, Marilyn Monroe did indeed create a persona, arguably one that masked her troubled self. She was a flirt in front of the camera. She posed, winked, smiled and batted her eyelids through innumerable portrait sessions and media frenzies; in every photo, she was a convincing picture of happiness, very often hiding the truth of her private life. There is a photograph by Ed Pfizenmaier of the renowned British photographer Cecil Beaton shooting an elegantly dressed Monroe, seated in a room at the Ambassador Hotel in New York, shortly before her trip to Britain. It typifies her ever-charming approach to the innumerable photography sessions she endured. Following that particular session, Beaton said of her that "she has a completely disarming, childlike freshness and ingenuity and her mischief is disarming".

That statement was very much in line with the general consensus, but some of the accompanying texts to the photographs in the exhibition reveal more of the "real" Marilyn – not the Marilyn who bathed in the limelight. An especially touching picture is that by George Silk for Life magazine, showing Monroe meeting the poet and biographer Edith Sitwell during a visit to Hollywood in 1952. They are sat together in lively conversation; one gets the feeling that Monroe, who sits facing Sitwell in a very ladylike fashion, knows there is a camera in the room, but it is more of a snapshot and somehow appears more honest than many of the glamorous pictures. When Sitwell recalled this meeting in her autobiography, she described Marilyn not as mischievous and charming, but as "very quiet...extremely intelligent...in her repose her face was at moments strangely, prophetically tragic, like the face of a beautiful ghost". In another picture, taken by Larry Burrows at the press launch of The Prince and the Showgirl at the Savoy Hotel in London, she sits facing away from the wall of flashbulbs, with a face that gives away her exasperation. We then see a completely contrasting Marilyn, happily waving at her fans gathered outside the hotel.

A good selection of magazine covers depicting Marilyn Monroe are also displayed in this exhibition, and show the love affair that the British had with this young star. It is a remarkably informative exhibition, given the small space afforded to it. It would have been interesting to see the photographs alongside, say, costumes, extracts from films, and so on, but that is, of course, outside the National Portrait Gallery's remit. It is perhaps not an exhibition for which a special trip should be made, but one which is worth seeing if you find yourself in the area with a spare half-hour or so. 

Marilyn Monroe: A British Love Affair , at National Portrait GalleryJulia Savage reviews Marilyn Monroe: A British Love Affair at the National Portrait Gallery.3