The 50th anniversary of the only successful theft in the history of London's National Gallery was "celebrated" yesterday, half a century after a brazen thief (or thieves) miraculously stole Goya's "Portrait of the Duke of Wellington" on August 21, 1961. Perhaps the most bizarre art theft in history, the Goya heist baffled police for years: someone had apparently climbed through an unlocked window into a bathroom in the National Gallery, evaded guards and a technologically sophisticated security system, and made off with a national treasure that had recently been at the center of controversy. 

The 1812 portrait of England's foremost war hero had been the property of the Duke of Leeds, who put it up for auction in March of 1961. Its purchase by an American oil tycoon outraged the British public. To prevent the removal of the painting from the United Kingdom, the British government invoked a rarely used law to freeze the sale. The government then hastily raised £140,000 (the equivalent of roughly £2 million, or $3 million, today), matching the sale price and thereby keeping the painting in England. On August 3, it went on display in the National Gallery where, thanks in part to the recent attention, it attracted huge crowds. Less than three weeks later, the painting disappeared.

The theft drew enormous media attention and captured the popular imagination. The painting appears in the first James Bond film, "Dr. No" (which happened to be filmed shortly after the theft), where it decorates the villain's Caribbean lair. Meanwhile, Scotland Yard's initial investigation centered on a bizarre ransom note, received three weeks after the theft, which implied that the painting was stolen as a protest over the BBC's licensing fee.

Surely this was a joke? Perhaps, but the author of the note identified marks on the back of the painting, suggesting he indeed possessed it. His flamboyant though somewhat childish letter expressed outrage that the British government would spend such a large sum on a painting while elderly citizens had to pay to watch television. The Goya would be returned, the ransomer suggested, if a charitable fund of equivalent value, £140,000, were established to pay for television licenses for old age pensioners.

The police refused to negotiate with the thief (British law forbade them from doing so). Then a second, equally bizarre ransom letter arrived:

"Goya Com 3. The Duke is safe. His temperature cared for — his future uncertain. The painting is neither to be cloakroomed or kiosked, as such would defeat our purpose and leave us to ever open arrest. We want pardon or the right to leave the country — banishment? We ask that some nonconformist type of person with the fearless fortitude of a Montgomery start the fund for £140,000. No law can touch him. Propriety may frown — but God must smile."

The police again declined to respond, prompting a third ransom letter, this one taunting the authorities:

"Terms are same.... An amnesty in my case would not be out of order. The Yard are looking for a needle in a haystack, but they haven't a clue where the haystack is... I am offering three-pennyworth of old Spanish firewood in exchange for 140,000 of human happiness."

When several years of investigation moved the police no closer to identifying the culprit, the Daily Mirror got into the act. The tabloid offered to exhibit the painting and raise money for charity if the thief returned it. A few weeks later, a note arrived at the newspaper's offices with a luggage check ticket for the Birmingham rail station. The ticket yielded an astonishing package — the stolen Goya, minus its frame. The painting had been deposited by someone identifying himself as "Mister Bloxham," presumably a reference to Oscar Wilde's "The Importance of Being Earnest," which features a Mrs. Bloxham and also an infant found in a handbag at a rail station luggage check.

The police were unable to track down"Mr. Bloxham." But a few months later an elderly man walked into a police station and announced, "I'm turning myself in for the Goya." The 61-year-old retired cab driver, Kempton Bunton, bore a striking resemblance to Alfred Hitchcock but no resemblance to Scotland Yard's profile of the Duke's kidnapper: an athletic, ingenious, professional art thief.  But Bunton confessed to the crime, and in one important respect his background dovetailed with the police profile: he had twice been fined for refusing to pay his TV license, an act of civil disobedience consistent with the motive for the theft suggested by the various ransom notes.

In other respects, however, Bunton's story didn't add up (starting with the fact that this portly, disabled elderly man seemed an improbable candidate to haul himself and a painting out a window and descend with it 14 feet).  Having been bedeviled for four years, the authorities chose to accept Bunton's confession at face value. 

The trial was almost as odd as the alleged theft. Bunton's lawyers made the curious argument that he could not be guilty of theft because he always intended to return the painting. The judge, a former professional rugby player, bought the argument and instructed the jury accordingly — telling them that unless they believed Bunton intended to keep the painting (unlikely, since he did return it), they must acquit. Accordingly, the jury found Bunton not guilty of stealing the painting but guilty of stealing its frame, since the latter was never returned. The judge sentenced him to three months in prison, accompanying this slap on the wrist with a little lecture: "Motives, even if they are good, cannot justify theft, and creeping into public galleries in order to extract pictures of value so that you can use them for your own purposes has got to be discouraged."

This outlandish theft sparked a change in U.K. law. In 1968, as part of England's new Theft Act, Parliament included a clause which made it illegal to "remove without authority any object displayed or kept for display to the public in a building to which the public have access" — regardless of one's motive or intent to keep or return the object. Under this law, which might as well have been called the Kempton Bunton Act, his "borrowing" of the Goya would have unambiguously been a felony.

There are important footnotes to this bizarre case. In 1969, several years after Bunton's conviction, someone else came forward claiming to be the culprit. Bunton took the opportunity to recant his own confession and assert his innocence, but after a brief investigation Scotland Yard concluded that the new confessor was not credible and Bunton was in fact guilty. In 1996, however, the National Gallery released a statement declaring that Bunton probably was innocent after all. This declaration came two decades too late to help Bunton, who passed away in 1977. But if the Gallery's statement was accurate, the world's strangest art theft remains unsolved to this day.

Meanwhile, television licenses were eventually revoked for old age pensioners, satisfying the thief's unusual ransom demands long after the fact. But last year, the licensing fee was raised as an issue again, finally resolved in October with the announcement that free licenses for pensioners will be extended until at least 2017. Somewhere, Kempton Bunton may be smiling down on us, whether or not he stole the painting.

Alan Hirsch is a lawyer and author of numerous books, most recently The Beauty of Short Hops: How Chance and Circumstance Confound the Moneyball Approach to Baseball. Noah Charney is a professor of art history and author of internationally best-selling books, with the forthcoming "The Thefts of the Mona Lisa: On Stealing the World's Most Famous Painting" (ARCA Publications 2011) to be published in August. He writes a regular column forARTINFO called "The Secret History of Art."

Together, Hirsch and Charney are writing a book on the theft of the "Duke of Wellington."