Since 1832, some of the greatest treasures of ancient Greek civilization have been residing in the British Museum. And the Greeks, who understandably consider themselves the rightful owners of things Greek, want their stuff back. The objects in question are the Elgin Marbles, so called because they were removed by Thomas Bruce, the seventh earl of Elgin, and British ambassador to Constantinople.

Elgin claimed to have removed the friezes and sculptures because the Ottomans (who ruled Greece at the time) were neglecting them. Of course, critics are more than happy to tell you the good earl outright stole them. Whatever Elgin’s motives, the workers who removed the sculptures did terrible, irreparable damage to the Parthenon. The marbles arrived in England between 1801 and 1805 to a mixture of awe and outrage. A profligate spender (earls just wanna have fun!), Elgin piled up huge debts and ended up selling the collection to Parliament in 1816. Since then, a cold war of sorts has simmered between the governments of England and Greece over the return of the sculptures. In fact, proponents of returning the marbles to Greece have removed Elgin’s name and refer to them simply as the Parthenon Marbles.

2. “Just Judges” Just Disappeared

The Adoration of the Mystic Lamb, a 24 panel masterpiece by Flemish painter Jan van Eyck, is considered one of the most important Christian paintings in history. One panel, however, known as the “Just Judges,” has been missing since it was stolen from a cathedral in the Belgian city of Ghent in 1934. Shortly after the theft, the archbishop received 13 ransom notes signed “D.U.A.” demanding 1 million Belgian francs for the painting’s safe return.

D.U.A. turned out to be a transposition of the initials of Arseen Van Damme (with the “V” unlatinized into a “U”), alias of Arséne Goedertier, an eccentric who allegedly got the idea from a detective novel. Since then, numerous theories about the theft and the whereabouts of the painting have circulated: It was stolen by the Knights Templar; or the painting contains a map to the Holy Grail; or it’s buried in the coffin of Belgium’s King Albert I; or Goedertier was working for a Nazi spy, who was ordered by Hitler to obtain it as the center piece of his new “Aryan religion.” The theories and clues have tantalized sleuths for three-quarters of a century, but the painting’s location still remains a mystery.

3. The Case of the Missing Munch

The Scream, Edvard Munch’s 1893 expressionist masterpiece depicting anxiety and despair, is one of the most famous paintings in the world. You’d be hard pressed to find someone who couldn’t recognize the ghostly figure on a bridge under a yellow orange sky, with hands clasped over his (or her?) ears, mouth open in a shriek. And on Sunday, August 22, 2004, administrators at Oslo’s Munch Museum were definitely given reason to let life imitate the art. In broad daylight, armed thieves barged into the museum, yanked The Scream and another famous Munch, Madonna, off the wall, then made a break for it. Police found only the getaway car and two empty frames. Understandably, Norwegians reacted with disbelief and outrage at the theft of two true national treasures, which wouldn’t turn up until 2006.

But this wasn’t the first time the painting had been purloined. There are actually four versions of The Scream. Another version was stolen in October 1994 from Oslo’s National Gallery. That one turned up three months later.

Weird note: August 22 is a bad day for paintings. On that day in 1911, the Mona Lisa was stolen from the Louvre.

            4. . Pahk the Cah, Then Steal Some Aht

On March 18, 1990, in what still ranks as the biggest art theft in U.S. history, two thieves made off with masterpieces worth—get this—over $300 million. The robbery occurred at Boston’s Isabella Stewart Gardner museum, where two men dressed as Boston cops pretended to respond to a disturbance. They cuffed the security guards, then helped themselves to 13 paintings, including works by Vermeer, Manet, and Rembrandt. While none of the paintings has yet been recovered, a theory has developed as to their whereabouts: the heist may have been masterminded by the Irish Republican Army, working in conjunction with Irish gangsters in Boston to ransom the paintings, then use the money to run guns to the IRA. Proponents of this theory say the paintings are hidden somewhere in Ireland, but IRA spokesmen vehemently deny this. Nevertheless, the FBI is said to be following this lead. Stay tuned.

5. The Disappearing Da Vinci

On Wednesday, August 27, 2003, two men posing as tourists walked into Drumlanrig Castle in Dumfries and Galloway, Scotland. During the tour, they made off with a painting, Madonna with the Yarnwinder, a masterpiece by Leonardo da Vinci valued at about £30 million. The thieves were seen on camera casually heading for their vehicle, a Volkswagen Golf GTI (whose slogan, “Getaway Drivers Wanted,” seems appropriate), with the incredibly valuable painting tucked under one arm. Over 500 years old, the painting had been in the possession of the family of the castle’s owner, the duke of Buccleuch, since the 18th century. In fact, the Madonna was the center piece of the duke’s art collection valued at over £400 million and including works by Rembrandt and Holbein. Despite the theft, the castle reopened to visitors days later.

In a 2007 Glasgow raid, officers recovered the painting and arrested four men – three from England and one from Scotland.

6. The Godfather of Fake

What made Elmyr de Hory infamous wasn’t the sheer number of forgeries he sold. It was that they were damn good forgeries. For 30 years, de Hory sold forgeries of paintings by the world’s greatest artists, including Picasso, Chagall, Matisse, Degas, and Toulouse Lautrec. In fact, his forgeries were so good, so precise in every detail, that they fooled even the most experienced art buyers. So much so that the native Hungarian has even attracted his own cult following, who pay high prices for “authentic” de Hory fakes. Irony of ironies, the forger’s forgeries are now being forged and sold by other forgers! Even more odd: today, legitimate museums host exhibitions of de Hory’s works.

De Hory told his story in Fake!, a 1969 biography by Clifford Irving (who went on to forge a phony autobiography of Howard Hughes). But in the end the master forger wound up penniless (just like a real painter) and committed suicide in 1976 – although rumors persist that he faked that, too.