Unlikely tales of fake tiaras and steel fleas: believe them if you want to fictional flea: believe it if you want to

THE DAY the Louvre and all its grave curators became April Fools is just over a hundred years ago. On 1 April 1896 Professor Heron de Villefosse, director of the department of Roman and Greek antiquities at the Louvre, announced to the French nation that he had acquired "a miracle of Greek goldwork": the Tiara of Saitapharnes.

He went on to describe the tiara's "unbelievable state of preservation", and "the unheard of richness of its motifs: art at its most delicate and pure". The tiara, said Heron de Villefosse, had been found in a burial mound in the Crimea, and it dated from the third century BC.

It certainly was - indeed, it still is - an amazing object. Made of gold and shaped like the tall conical tiara of a Pope, it is decorated with bands of ornament. One shows classical Greek scenes from the Iliad, while another illustrates daily life among the Scythians - the pastoral nomad people who lived on the northern shore of the Black Sea and traded with the Greek colonists there. Around the tiara runs an inscription: "from the Senate and people of Olbia to the great invincible King Saitapharnes".

For the Louvre experts, those words clinched the authenticity of the tiara. At the site of Olbia, a Greek port city near the estuary of the Dnieper, a well-known inscription had been found which mentioned the city's gratitude to Saitapharnes, a local Scythian ruler, for his protection. How the citizens had shown their gratitude had not been known, because the inscription was incomplete. But now the mystery was solved.

So began one of the great disasters of early museum history. No wonder the object's state of preservation was unbelievable - it had been made only two years before. And a number of scholars said loudly and at once that the tiara was a fake. But the Louvre dug itself in. Doubts about the tiara were dismissed as the envy of foreign curators in rival museums. It took seven years of frantic denial in the teeth of overwhelming evidence before the museum finally gave in and took the tiara off display.

Even now, the tiara is not a popular topic there. Only ten days ago, I was curtly refused leave to see it. As the scholar Alain Pasquier wrote a few years ago, "this object, which provokes the occasional laugh at the Louvre but the sort of laugh which gets discreetly strangled in the throat, still emits unease; it is like an obscene thing whose malignity one would like to exorcise, like an ancient remorse one tries to suppress, like a family's cupboard skeleton which one tries to forget about..."

The tale of the tiara goes back to Odessa, in the 19th century a city as new and wild and rich as San Francisco, and to the genius of its Jewish craftsmen. In about 1890, a young man called Ruchomovsky arrived in Odessa from Mozyr, now in Belarus. His parents had wanted him to become a rabbi, but he preferred to develop his extraordinary talent as a goldsmith. In Odessa, he got to know two brothers called Hochmann, who ran a grain business at Ochakov, near the site of Olbia, but who also made money by commissioning fake Greek and Scythian relics from Odessa jewellers. Ruchomovsky did not need to forge anything, for he already had a wonderful reputation. He had spent nine years making a miniature gold coffin containing a gold skeleton with 167 moving parts. The Hochmanns loved both his talent and his innocence. They decided to use him.

A professor in Kharkov was retiring, they said, and his admirers wanted to present a Greek-style bit of finery to him. The brothers showed Ruchomovsky some illustrations and the text of the Olbia inscription. He set to work, apparently in good faith. But when he had finished the tiara, the Hochmanns set off for the museums of central and western Europe to peddle Ruchomovsky's work as a genuine antiquity. They paid him the rouble equivalent of 5,000 gold francs for it. Their agents sold it to the Louvre for 200,000 gold francs. Not bad business! But eventually the row over France's new treasure reached Odessa. Ruchomovsky was less interested in getting a cut of the Hochmanns' than in establishing that he was not a deliberate forger. He set off for Paris, and arrived there in 1903.

By now, the Louvre had its back to the wall. Museum directors and archaeologists all over Europe and Russia had denounced the tiara. The famous excavator Nikolai Veselovsky and Dr Stern, curator of the Odessa Museum, had both warned that they were offered forged Greek goldwork every month of the year, and Stern was quick to suspect the hand of Ruchomovsky in the tiara. The mighty Furtwangler of Munich declared that its decoration was "an empty mishmash" of imitation, and that only some of the bronze rivets might be genuinely old. But the Louvre held out, mostly out of patriotic arrogance but also on the desperate argument that no fumble-fingered Russian was capable of such exquisite workmanship.

In Paris, Ruchomovsky was lionised by the press and public, who longed to see the proud Louvre brought down a peg. With the aid of his original sketches, he showed how he had designed and made the tiara. When even this did not move the museum directors, he borrowed tools and began to reproduce the tiara's bands of ornament. This was the death blow. In March 1903, a sombre communique announced that the Louvre had asked the permission of the Ministry for Arts and Education to withdraw the tiara from display. Barnum's Circus offered to buy it at its original price for inclusion in a travelling show of freaks and curiosities. Grimly, the Louvre refused this last humiliation.

Russia laughed, and is still laughing. To Russians, the affair recalls a famous story by Leskov called "The Cross-eyed, Left-handed Artificer and the Steel Flea". In this story, Tsar Alexander the First visits England where craftsmen, anxious to prove England's technical superiority, present him with a box containing a steel flea, visible only through a microscope but complete with a minute key to wind it up and make it jump. On his return, the Tsar challenges the best artificer in the ironworks of Tula (and Russian museums to this day contain Tula padlocks no bigger than a grain of wheat) to save Russia's honour.

After weeks of frantic work, the flea is returned to the Tsar. Under the microscope it looks much the same, until the artificer points out that he has put horseshoes on all the flea's feet, each shoe inscribed with the maker's name and held in place by infinitesimal nails.

The tale of the Tiara of Saitapharnes is about the cultural arrogance of 19th-century nationalism, when the breakfasts of emperors or presidents could be spoilt by news that a rival nation had acquired a finer Greek treasure or devised a better steel flea, and museums flaunted their acquisitions as if they were imperial conquests in Africa. But the tale is also about the riddle of what is real and what is a fake, and why one should be more valued than the other.

Ruchomovsky made something beautiful, and the deceit was not his. It was the Hochmanns who swindled both him and the Louvre, and transformed a respectful pastiche into a fraud. So is it right to call the tiara itself a fake?

The obscure province Ruchomovsky came from is now an independent state called Belarus, which is still trying to invent a historical pedigree. Is Belarus a fake because its official history is untrue, or real because many of its own people believe in its identity? The answer to those questions is also the secret of the tiara. From its Louvre drawer, it still emits waves of ambiguity which make fools of us all.