Jean Hardouin (1646-1729) was not himself a forger, but he was the author of an unusual theory about forgery. As librarian of the Lycee Louis-le-Grand in Paris, he came to the conclusion that virtually all classical texts, and most ancient works of art, coins and inscriptions, had been forged by a group of thirteen-century monks led by a mysterious figure whom he called Severus Archontius. The goal of this group was supposedly to "establish Atheism amongst men, by paganising all the facts of Christianity". The name Severus Archontius was probably a veiled reference to the Holy Roman Emperor Frederick II of Hohenstaufen.

Hardouin was, at the time he first proposed his theory in 1693, a highly regarded scholar. Other learned men tried to take him seriously and argued the merits of his theory with him, but as he persisted in his views, he gradually came to be seen as a pariah in the scholarly community. One contemporary described him as "very confident, arrogant, and violently addicted to hypothesis and paradox." His critics referred to his theory dismissively as "Harduinismus".

Hardouin claimed he "detected the whole fraud" by spotting a series of clues embedded in classical works, clues that included instances of poor writing as well as apparent anachronisms. He believed the thirteenth-century forgers had not only forged the core classical texts, but also a range of later references to these texts, thereby creating a vast web of mutually reinforcing deception.

A nineteenth-century historian remarked that, "The legitimate inference from his theory is that he wished to establish Romanism on the ruins of universal learning, and to reduce mankind to an implicit submission to the Popedom: for, to the obvious question, which he states himself, 'If we must not believe the Fathers, whom can we believe?' he boldly replies: 'Not the Fathers, I say, but our Holy Mother the Church of Rome.'"

Viewed in a broader context, Hardouin's theory can be seen as an extreme expression of a growing awareness amongst seventeenth-century scholars of the number of errors, exaggerations, and inventions in the historical record.

The Ghostly Drummer of Tedworth was a case of suspected poltergeist activity. In the early 1660s John Mompesson of Wiltshire began to hear strange noises in his home. There was the sound of a drum beating, as well as scratching and panting noises. Objects seemed to move of their own accord in the house, and sometimes a strange sulphureous smell lingered in the air.

Mompesson believed that a man he had helped send to jail, a drummer named William Drury, had, through some form of witchcraft, caused a malevolent spirit to invade his home. The case attracted interest throughout England, and many people came to witness the spirit for themselves. However, when the King sent two representatives to investigate the haunting, they found no evidence of supernatural activity.

Skeptics, of which there were many, dismissed the entire thing as a hoax. They suggested that Mompesson himself may have been behind it, either to profit from those who came to see the spirit, or to decrease the value of the house (which was rented). Another possible culprit was Mompesson's servants, who seemed quite pleased at the travails of their master, and who often taunted him by pointing out that he could never fire them because no one else would agree to work for him under such conditions. More >>>

The Cerne Abbas Giant is a chalk figure of an enormous naked man wielding a club carved into the side of a hill in Dorchester, England. The giant is one of a number of presumably ancient hill figures that dot the English countryside, such as the Long Man of Wilmington and the White Horse of Uffington. But the Cerne Abbas giant is uniquely distinctive because of the enormous erect phallus that he sports.

The giant occupies a treasured place in British culture. He's widely believed to have been carved thousands of years ago. Folklore suggests he's an ancient fertility god, possessing the power to make childless women pregnant. Postcards of him are the only images of a naked man accepted by the British post office. But in recent years historians have suggested that the Giant may date only to the seventeenth-century, since the first written reference to it only dates to 1694. Furthermore, its creation may have been a prank. More >>>

An 8-page pamphlet published in Paris in February 1637 described an unusual case of pregnancy without intercourse.

Magdeleine d'Auvermont of Grenoble, said the pamphlet, had recently given birth to a son, Emmanuel. But when she did, her relatives immediately accused her of adultery and brought her to trial to have her child declared illegitimate.

Their case seemed airtight. After all, Magdeleine's husband had been absent for the past four years. However, Magdeleine insisted she had been chaste, and she offered an unusual explanation of how she had become pregnant. She said that she had dreamed of having sex with her husband, and the next morning had felt the signs of pregnancy. Nine months later she gave birth to her son.

During the trial, four midwives testified that they themselves had become pregnant without intercourse, and four doctors from the University of Montpellier signed a certificate stating that such a thing was possible. The Grenoble judges voted that her absent husband was indeed the father of the child, and that the child was therefore legitimate.

The report of this ruling caused an uproar. But when the Parliament of Paris considered the case later that year, it decided that the report had to be a hoax. It noted the names of the mother and son, which suggested a parody of the birth of Christ, as well as the fact that the sentence from Grenoble was delivered on Carnival Day.

In 1593 reports began to spread of a young boy in Silesia, seven-year-old Christoph Müller, who had grown a golden tooth. Jakob Horst, a professor of medicine at Julius University in Helmstedt, decided to investigate. He found the boy did indeed have a gold tooth set firmly in his jaw. Tests with a touchstone (a small tablet of dark stone on which soft metals such as gold leave a visible trace) confirmed the gold was real, though not as high quality, Horst noted, as Hungarian gold.

Horst wrote a 145-page treatise about the case, De aureo dente maxillari pueri Silesii (Of the Golden Tooth of the Boy from Silesia), in which he attributed the golden tooth to astrological causes. He noted that the boy was born on December 22, 1585, when there was an unusual alignment of the planets that must have increased the heat of the sun, causing the bone in the boy's jaw to turn to gold. He also argued that the tooth was a portent of important events to come: the dawn of a new golden age for the Holy Roman Empire. However, because the tooth was located on the boy's left side, considered to be the sinister side, the golden age would be preceded by many calamities. More >>>

Carlo Sigonio was a highly respected Italian scholar who specialized in the history of Rome. Around 1583 he claimed that he had discovered a new complete work by the great Roman orator Cicero. It was titled De Consolatione or the Consolation. In it Cicero grieved for his daughter's death. Only small fragments of this work had ever been found before.

The discovery of this manuscript caused great excitement. But when other scholars read it, the general consensus was that it had to be a fake. It contained numerous anachronistic phrases and Italian mannerisms that Cicero would never have used.

Sigonio stubbornly defended the work, but today it is still regarded as being a forgery. Sigonio might have written the book himself, perhaps to display his mastery of Ciceronian scholarship.

Martin Guerre, a French peasant, married Bertrande de Rols in 1538. She bore him one son. But in 1548, after a falling out with his father, Martin disappeared. Eight years passed without any sight of him. Because of Catholic law, Bertrande could not remarry. But in 1556 Martin suddenly returned. Or did he?

The man who claimed to be Martin Guerre was similar in appearance and knew many details of Guerre's life. Bertrande accepted him as her husband, and lived with him for three years, bearing him two children. But when the new Martin sued his uncle for part of the inheritance of his father, the uncle became suspicious and accused him of being an impostor. Specifically, the uncle claimed that the new Martin was actually Arnaud du Tilh, a man from a nearby town.

The case went through a series of trials and appeals. The court seemed to be favoring the authenticity of the new Martin, until suddenly the original Martin Guerre showed up. He had been serving in the Spanish army, where he had lost a leg.

The fake Martin Guerre was executed. The real one eventually reconciled with his wife, who bore him another child.

A film based on the story of Martin Guerre was released in 1982.

Michel de Notredame (1503-1566), better known as Nostradamus, rose to prominence as an astrologer in sixteenth-century France. He was supported by the patronage of Queen Catherine de Médici, for whom he wrote numerous verses implying the downfall of her rival, Elizabeth I of England. Obviously, these predictions did not come true. His most popular work was The Prophecies, first published in 1555, which has remained in print to this day.

Nostradamus himself cannot properly be regarded as a hoaxer since astrology in his time was a highly respected practice. He believed in the legitimacy of his art. The real deception lies in the uses to which his work has been put since his death.

Nostradamus wrote his prophecies in an ancient form of French worded so ambiguously that it could be interpreted to mean almost anything a reader desired. As a result, his followers have been able to credit him with predicting a wide range of calamities including the great London fire of 1666, the rise of Adolf Hitler, the Iranian revolution of 1979, and the events of September 11, 2001. However, Nostradamus's supposed predictions are only ever noted after the fact. There has never been an instance in which a verse by Nostradamus has been used to accurately predict an event before it occurred.

The work of Nostradamus has also been a theme in a large number of outright hoaxes—instances in which verses were falsely attributed to him. For instance, during World War II the Nazis spread propaganda claiming that Nostradamus had prophesied the success of Hitler. The Allied countries retaliated by spreading propaganda claiming Nostradamus had foreseen Germany's defeat. After 9/11 interest in Nostradamus surged thanks to some verses of his, circulated by email, in which he seemed to predict the tragedy. However, the verses had not actually been written by him. They were the work of an anonymous hoaxer.

Medieval naturalists had a great appreciation of hoaxes, and they spent a lot of time collecting and studying them. However, they didn't call them hoaxes. Instead, they called them Lusus Naturae, or Jokes of Nature. The term Lusus Naturae described any creature or specimen that defied classification. One famous example was the Scythian Lamb, or Vegetable Lamb. This bizarre creature, which medieval naturalists were sure existed, although they couldn't locate a specimen, was part plant and part animal. It consisted of a lamb from whose belly grew a thick stem that was firmly rooted in the ground. Thus rendered immobile, the creature survived by eating the grass which grew around it. Medieval naturalists labelled the creature a Lusus Naturae because it defied classification, being neither plant nor animal. More >>>

Mother Shipton was a sixteenth-century Yorkshire seer who supposedly made a number of startlingly accurate predictions. However, it is uncertain whether she actually existed, and many of the predictions attributed to her are outright hoaxes.

The first extant reference to her is found in a booklet, The Propheceyes of Mother Shipton, published in 1641, eighty years after she was said to have died. This work claimed she had accurately predicted the deaths of a number of her contemporaries such as Cardinal Wolsey. However, there are no written references to her, or her predictions, during her own lifetime.

Other works about Mother Shipton subsequently appeared, and with each work new prophecies were credited to her. However, all the prophecies were backdated prophecies (i.e. prophecies which described events that had already occurred).

Mother Shipton's most famous prophecy was that, "The world to an end shall come / In eighteen hundred and eighty-one."

These lines circulated widely throughout England as 1881 approached and caused great popular concern. However, this prophecy was actually the work of a Brighton bookseller, Charles Hindley, who in 1862 had published what he claimed to be a reprint of a 1684 biography of Mother Shipton. To make the biography seem more relevant to nineteenth-century audiences, Hindley had inserted some new verses of his own creation into the book. Some of the other verses Hindley wrote made it seem as if Mother Shipton had accurately predicted the invention of technologies such as the railway, telegraph, submarines, and hot-air balloons. More >>>

The Voynich manuscript is a mysterious book consisting of approximately 240 pages of hand-written text and crudely drawn illustrations that depict plants, astrological diagrams, and naked women. The text is written in an unknown alphabet that has defied all attempts at translation. It is not certain exactly how old the manuscript is, but it appears to date to around the late fifteenth century. It is named after Wilfrid Voynich, who acquired it in 1912 from the library of Villa Mondragone, a Jesuit college in Frascati, Italy. More >>>

In 1496, when he was a young man, Michelangelo sculpted a sleeping cupid. He, or an accomplice, then buried it in acidic earth to give it an appearance of great age. The plan was to pass it off as an antiquity, which would allow it to fetch a higher price.

The artificially aged sculpture was sold through a dealer to Cardinal Raffaello Riario of San Giorgio. Eventually the Cardinal learned of the forgery, and he demanded his money back from the dealer. However, the Cardinal was so impressed by Michelangelo's obvious talent that he didn't press charges against the young artist. To the contrary, he allowed him to keep his percentage of the sale.

Michelangelo’s cupid eventually came into the possession of the d’Este collection in Mantua, where it was reportedly displayed side by side with a genuine antique sleeping cupid. But it is believed that the statue was destroyed in a fire in 1698. Even though it was a "fake", it would be considered priceless today, if it still survived.

Count Jean V d'Armagnac (1420-1473) was described by a contemporary as "short and stocky of stature, even pot-bellied, but gifted with great bodily strength. His neck was short, surmounted with an acne-pocked visage, with squinty eyes, crowned by a shock of red hair."

The Count fell in love with his younger sister, Isabelle, whom he affectionately called ma mia costa (my own rib). She was said to be one of the great beauties of her time. He had two sons with her, after which he sought approval from the Pope to marry her. The Pope refused.

Undeterred, the Count bribed a papal official, Antoine d'Alet, Bishop of Cambrai, to forge a papal bull allowing the marriage. A few months later, the Count and his sister had a third child together, a daughter. The three children were known as the Bastards of Armagnac. Isabelle referred to them in public as her niece and nephews, which technically they were.

When the Pope learned of what the Count had done, he excommunicated him. Eventually the Count married another woman (not related to him).

Later the Count rebelled against King Charles VII of France, who sent an army to crush him. The army killed the Count and dragged his body through the streets. They locked his wife, seven months pregnant, in a cell with her husband's dead body. Her child (the Count's one legitimate heir) was stillborn, thus ensuring the end of the House of Armagnac.

Crowland Abbey, located deep in the Lincolnshire fens of England, was once a center for medieval religious life. Today, however, it lies mostly in ruins. A few quatrefoil window carvings and undamaged statues provide a sense of the building's former glory, but the abbey itself is less well known for its artwork than it is for an outrageous historical hoax that its former inhabitants once perpetrated. More >>>

The Travels of Sir John Mandeville, which first appeared in print around 1371, purported to document the travels of an English knight throughout Egypt, Ethiopia, India, Persia, and Turkey.

The book was very popular, and was regarded as being factual by medieval scholars, but modern readers can easily spot that the majority of it is fiction. For instance, it describes islands whose inhabitants have the bodies of humans but the heads of dogs, a tribe whose only source of nourishment is the smell of apples, people the size of pygmies whose mouths are so small that they have to suck all their food through reeds, and a race of one-eyed giants who eat only raw fish and raw meat.

Mandeville himself was probably also a fictional character. The name might have been adapted from an earlier French romance titled Mandevie that also involved a hero who embarked on an imaginary journey. The true author of the book remains unknown. More >>>