Stamps to high art, Queen Elizabeth II is the UK's public face

How the United Kingdom's reigning monarch became, and remains, one of the most recognisable people in the world.

British postage stamps are unique. They’re the only ones issued anywhere in the world that do not bear the name of their nation. Instead UK stamps are identified by an image of the reigning monarch.

Though Queen Elizabeth II has been busy all spring, tomorrow marks the official Central Weekend celebrations of her 60 years on the throne of the United Kingdom of Great Britain and Northern Ireland. And no doubt the beloved monarch, as she attends the Epsom Derby, a BBC concert and various luncheons, won't disappoint royal-watchers in her choice of clothing, with her penchant for bright colours and coordinated outfits. "I can never wear beige because nobody will know who I am," she once told the royal biographer Robert Hardman.

She was obviously joking. Elizabeth Alexandra Mary Windsor, celebrating her Diamond Jubilee as the Queen, is surely the world's most recognisable woman. And not least because of the fact that her face has been the subject of more portraits and images than perhaps any other person in history.

The many and changing images of the British monarch from the past 60 years are the focus of a major exhibition at The National Portrait Gallery (NPG) in London called The Queen: Art and Image, running until mid-October. Paul Moorhouse, the curator of the show, says that, while there have been thousands of different renditions of the Queen's portrait over the years, they can only reveal so much of this beloved monarch. "[She is] familiar to millions around the globe but for the man or the woman in the street, she is seen from afar.

"The impressions of her in the minds of ordinary people are not based on reality, but on innumerable visual representations. Her thoughts and opinions on many subjects remain undisclosed."

Queen Elizabeth was born on April 21, 1926, when television was just an experiment (she has since become the first mass-media monarch, with a Facebook presence, Christmas TV broadcasts that can also be seen on YouTube and even an indirect Twitter link). Her visibility started with a childhood trickle of officially sanctioned and sedate photographs, and paintings of her with her sister Margaret at play or in posed portraits by such society snappers as Cecil Beaton. The first known painting was of her at the age of seven by a Hungarian artist called Philip de Laszlo.

But early in Elizabeth's childhood, her uncle, King Edward VIII, abdicated the throne over his love for the American divorcée Wallis Simpson. This made her father become King George VI and Elizabeth his heir, thrusting her into the frenzied public eye ever since. As a result, her image has been seen all over the world; and not just in picture galleries.

While many believe that the Mona Lisa is the world's most reproduced artwork, that honour actually belongs to a little picture of Queen Elizabeth by an artist called Arnold Machin. He is hardly a household name, yet at the time of writing, more than 220 billion copies of his image - used on British postage stamps -have been produced in the 45 years since it was introduced.

The Queen's face has also adorned every UK coin since she came to the throne and all English banknotes since 1960, not to mention those of other countries in the Commonwealth such as Canada, Turks and Caicos Islands and Gibraltar. She has featured on the coins and paper money of more countries than anyone else in history.

But the public fascination with royalty and Elizabeth moves far beyond mere money and stamps. She has been a favourite subject for photographers, painters and artists of other mediums for more than half a century; she's even had amiable parodies in satirical TV programmes such as the puppet show Spitting Image, film portrayals including Helen Mirren's Oscar-winning portrayal in The Queen, and innumerable newspaper cartoons.

Not every depiction has been complimentary, however. The graphic artist Jamie Reid's image of her with a safety pin through her nose became a defining image of punk when used by the Sex Pistols, while the extreme conceptual artist Genesis P-Orridge received a suspended jail sentence for juxtaposing her face with pornographic images.

Even some established artists have upset the nation. After Lucien Freud - grandson of Sigmund Freud and acclaimed as one of Britain's greatest modern portrait painters - portrayed her in 2000, one critic said the resulting image (included in the NPG show) was so ugly Freud should be imprisoned in the Tower of London. Another said it made her look like a royal Corgi (the Queen's favourite breed of dog) that had suffered a stroke.

But her dignity has not been tarnished by such ignominies. Every British embassy, consulate and high commission around the world displays an official portrait. The latest, created a few weeks ago, is by the photographer John Swannell, a seasoned royal photographer. Of one previous sitting he said: "I had to shoot the Queen Mother, the Queen, Prince Charles and Prince William all together, and they said: 'You realise when you shoot this it'll be the most important photograph since Queen Victoria was photographed with her family?' I said: 'Oh great, how long have I got to do it?', and they said: 'Ten minutes!' You're allocated a time slot because they're so busy. You've really got to work fast."

Another painted portrait, included in the NPG show, is by the Florentine-born artist Pietro Annigoni. The painting, a 1969 image of the Queen in a red cloak, is said to be one of the Queen's favourite paintings of herself. She liked it so much that she purchased an early study of it in 2006 for an undisclosed sum. "I did not want to paint her as a film star," said Annigoni. "I saw her as a monarch, alone in the problems of her responsibility."

But portraiture is no longer limited to painting and photography. In 2004, the holographic artist Chris Levene was commissioned by the Bailiwick of Jersey to create a portrait to mark 800 years of allegiance to the Crown. It has just been given to the NPG. Two sittings were involved using a high-resolution camera, a 3D data scanner and a standard medium-format camera. The resulting and most publicised image is startling - the Queen has her eyes closed.

"The Queen had a great knowledge of photography," said Levene. "By the time we had finished I had a genuine sense of warmth for her. She is a quite extraordinary lady. As a model she has done many sittings and she is really radiant."

But for all of these billions of images, just how much do we really know of the Queen? She does not give interviews and the artists and photographers who've created portraits from life are dutifully tight-lipped about any conversations in the studio. A familiar facade conceals a very private personality.

The closest recent portraitists have come to spilling the beans on conversations during the work-in-progress sessions was the Australian television presenter and artist Rolf Harris. After he had finished a painting in 2008, he said the Queen had confided: "I'm only too happy to be sitting absolutely motionless, doing nothing."