La Gioconda, or Mona Lisa, c. 1503–1506 by Leonardo da Vinci

Editor's Note: Dianne Hales is the author of Mona Lisa: A Life Discovered and La Bella Lingua: My Love Affair with Italian, the World's Most Enchanting Language. Here, Dianne joins Biographile to discuss the odd, inexplicable things people do when faced with the Mona Lisa, exemplifying the bizarre syndrome known as the Stendhal Syndrome. From acts of aggression, to lust, to selfie-infatuation, behold the myriad acts of mania the Mona Lisa induces. 

Presidents and princes lauded her. Poets penned sonnets to her. Singers crooned of her. Admirers reproduced her image in beads, bread, bulbs, jellybeans, Legos, seaweed and just about every other material imaginable.

But Leonardo da Vinci's model has stirred more than adulation. A vandal threw acid at the lower part of the painting. A young Bolivian flung a rock, chipping the left elbow. A Russian woman distraught over being denied French citizenship hurled a souvenir mug. The portrait, barricaded behind bulletproof glass, was unharmed.

The attacks stem, according to art experts, from the same source as the admiration: the deep passions Leonardo's lady evokes. But don't blame his model. As I discovered in years of tracing her life, Mona (Madame) Lisa Gherardini del Giocondo (1479-1542) was the proud daughter of an ancient Tuscan clan, the teenaged bride of a prosperous silk merchant twice her age, the mother of seven (including a stepson), a devout Catholic and, in her husband's words, a "noble spirit." As a refined woman of Renaissance Florence, she would have been horrified by the outbursts.

So why does her portrait trigger such intense reactions? Start with Leonardo, who with thousands of feather-light strokes captured the immediacy of a real, breathing human being centuries before the invention of the camera. His masterpiece, the art historian Giorgio Vasari wrote, "would cause every brave artist to tremble and fear." No one could have predicted its effect on mere mortal onlookers.

For centuries, the portrait resided in princely palaces, admired by an elite few. Only after the French Revolution liberated "the people's art" did Mona Lisa go on public display in the Louvre.  As Romanticism swept  across Europe in the 19th century, hers became the face that launched a thousand fantasies. Suitors bearing flowers and impassioned notes climbed the grand staircase of the Louvre to gaze into her "limpid and burning eyes."

"Lovers, poets, dreamers go and die at her feet," a French curator wrote in 1861. He wasn't exaggerating. The artist Luc Maspero threw himself from the fourth-floor window of his Paris hotel, leaving a farewell note that said, "For years I have grappled desperately with her smile. I prefer to die."

Emotions intensified after a thief stole the Mona Lisa in August, 1911. Millions mourned as if a person rather than a painting had gone missing. By the time of her return to the Louvre in 1914, Mona Lisa had been transformed into art's first mass celebrity, famous for being famous, part of the public domain that anyone could use – or abuse.

The artistic affronts began with Marcel Duchamp, who painted a mustache and goatee on a postcard of the Mona Lisa and called it L.H.O.O.Q. (letters that, when spelled in French, sound like slang for "she's got a hot ass"). Dali, Magritte, Warhol and other modern masters couldn't keep their hands off her. Contemporary artists have pushed the parodies ever further with works like Gorilla Lisa,  Gaso Lisa (drenched in oil) and Unicorn Mona (with a horn in the middle of her forehead).

Mona Lisa human imitations have ranged from Lady Gaga's  recent appearance in  a portrait poncho and sallow make-up to runway models' shaving their eyebrows to mimic her browless look. Most extreme are the women who have undergone plastic surgery to look like Leonardo's muse, including a  performance artist who had her operation videotaped.

But looking at — or looking like – the portrait is giving way to a new form of Mona Lisa mania: snapping selfies with her.  After centuries of inciting every emotion awe to anger, La Gioconda — the "Happy Woman," as the painting is known in Italian – is inspiring a reaction not even visionary Leonardo could have iimagined: visitors making duck faces next to his muse as they bask in 15 seconds of Instagram fame.