A self-portrait defaced by the artist after an onlooker called it "flattering" is going on display at the National Portrait Gallery complete with slash marks.
Scottish artist Craigie Aitchison, who was known for his aversion to self-promotion, cut the portrait after a visitor to his studio said the painting made him look good.
But he was later persuaded by the National Gallery's head of conservation Martin Wyld to let him restore it, with the lacerations remaining visible.
The painting remained in the artist's possession until his death in 2009 and the National Portrait Gallery has now bought it, with funding from the likes of fashion designer Sir Paul Smith.
Paul Moorhouse, the gallery's curator of 20th century portraits, said: "Craigie Aitchison was a highly distinctive artist whose singular vision was rooted in an acute sensitivity to colour and subtle implications of meaning.
"We are delighted that this fascinating self-portrait survived the artist's momentary destructive doubts and can now be seen by future generations."
The world's most famous painting has been the subject of numerous thefts and attacks. It went missing for two whole years in 1911 when Louvre employee Vincenzo Peruggia stole it, trying to return it to Italy. 1956 was a bad year for Mona. Not only was it doused in acid but later that year a young Bolivian named Ugo Ungaza Villegas threw a rock at it, chipping some of the paint off. This incident prompted the decision to house the painting in bullet-proof glass.
In 2012, a well-meaning but artistically incompetent pensioner decided to attempt a restoration of <em>Ecce Homo (Behold the Man)</em> by Elias Garcia Martinez, a highly-prized 100-year-old fresco of Christ. It didn't work.
The very nature of Banksy's work means that his pieces are often at the mercy of vandals although he seems to suffer more at the hands of over-zealous councils and builders. His <em>Parachuting Rat</em> (pictured) piece fell foul of an Australian building firm who decided to drill a hole through it to install a bathroom pipe.
The Night Watch
Rembrandt's<em> The Night Watch</em>, was attacked with a bread knife by an unemployed teacher named Wilhelmus de Rijk, in 1975.
Diego Velázquez's <em>The Rokeby Venus</em> was attacked with a meat cleaver by militant suffragette Mary Richardson. This black and white picture clearly shows the damage. Richardson was jailed for six months.
The Little Mermaid
Quite why <em>The Little Mermaid</em> causes such outrage is beyond us but the statue has been defaced many times since it was placed in Copenhagen harbour in 1964. Edvard Eriksen's mermaid has been decapitated twice (once by Jorgen Nash and the Situationist Internationale), had her left arm sawed off and had holes blasted in her wrists and knees. Painful.
The Fall of the Damned
<em>The Fall of the Damned</em> by Peter Paul Rubens is a monumental piece of art measuring more than two metres square. In 1959 a vandal threw acid on it. According to the culprit, he did not directly destroy the work, claiming the acid "relieves one from the work of destruction", whatever that means.
<em>Danaë</em>, by Rembrandt, was attacked in 1985 by a clinically insane gentleman who threw sulfuric acid on the canvas and cut it twice with his knife, causing horrific damage. The entire central part of the painting was destroyed but extensive restoration managed to salvage it.
In 1845 a rather intoxicated William Lloyd took issue with this vase and threw another sculpture on top of it, smashing it to pieces. Lloyd was jailed for two months.
With a cricket bat concealed in his trousers, Paul Kelleher sneaked into London's Guildhall Art Gallery and decapitated the Iron Lady. After waiting for police to arrest them he said simply: "I think it looks better like that."
Pablo Picasso's famous ant-war masterpiece <em>Guernica</em> came a cropper in 1974 when a vandal spray-painted it with the slogan 'Kill Lies All'. PA
Away from the Flock
Damien Hirst's lamb in formaldehyde, <em>Away from the Flock</em>, wasn't safe from vandalism despite being in a glass case. Mark Bridger poured black ink into the tank in 1994 whilst it was on display at the Serpentine Gallery. PA