In a medieval mystery of the Catholic Church lies evidence of a woman pope, with clues buried in ancient parchment, artwork and writings, even in tarot cards and a bizarre chair once used in a Vatican ritual.
Was there a Pope Joan -- a woman with nerve enough to disguise herself as a man and serve as pope for more than two years in the ninth century? It is one of the world's oldest mysteries. Her story first appeared in histories written by medieval monks, but today the Catholic Church dismisses it.
"Ninety percent of me thinks there was a Pope Joan," says Mary Malone, a former nun who wrote a history of women and Christianity.
Donna Cross, a novelist who spent seven years researching the time period, says the historical evidence is there. "I would say it's the weight of evidence -- over 500 chronicle accounts of her existence."
Life was often short and brutal for women living in A.D. 800.
"No woman would have been allowed to appear on the streets in public," says Malone. "That named you as a prostitute immediately. Women were confined to their homes."
In the town of Mainz, Germany, where it is thought the girl who might have became Pope Joan grew up, most people lived in mud huts. The average life span was only 30 or 40 years.
But English missionaries were bringing Christianity to Germany, and they created a monastery called Fulda, which became a center of education, books and conversation for travelers -- but it was only for boys.
In his "History of Emperors and Popes," a monk named Martin Polonus, who was a close adviser to the pope wrote about a young woman from Mainz who learned Greek and Latin and became "proficient in a diversity of branches of knowledge."
Cross and other historians say a girl studying at the monastery would have no choice but to disguise herself as a boy. But how was it possible to keep the secret?
"First of all, you might want to remember that clerical robes are very body-disguising," says Cross. "Also, in the ninth century, personal hygiene was nonexistent. Nobody bathed. They washed their hands, their face, their feet, but they didn't bathe."
Also, clergy members were required to be clean shaven, and malnutrition made most men and women physically gaunt.
Polonus wrote that this woman was "led to Athens dressed in the clothes of a man by a certain lover of hers." Then, according to the 500 accounts, the woman made her way to Rome.
In the ninth century, Rome and the Vatican were nothing like today's solemn and civilized center of culture and faith. Then the center of the Christian faith was home to bawdy monks, scheming cardinals, cross-dressing saints, intrigue, melodrama, corruption and violence.
"Popes ... killed each other off, hammered each other to death," says Mary Malone, the former nun. "There were 12-year-old popes ... we have knowledge of a 5-year-old archbishop. ... It was a very odd time in history."
That also means it would have been a time of opportunity for someone with ambition and nerve. The chronicles say that's how Joan, known as John Anglicus, or English John, became secretary to a curia, a cardinal, and then, as Polonus writes, "the choice of all for pope" in the year A.D. 855.
If you travel to Italy and ask questions about Pope Joan, many people will direct you toward the clues embedded in art, literature and architecture.
The Renaissance poet Giovanni Boccaccio, best known for writing "The Decameron," also wrote a book on "100 Famous Women." No. 51 is Pope Joan.
Rare book dealers in Rome pull ancient tarot cards from their shelves. The card for hidden knowledge is "La Papessa" -- the Female Pope.
Travel north to Siena to the Duomo, where inside the cathedral is a gallery of terra-cotta busts depicting 170 popes, in no particular order. In the 17th century, Cardinal Baronuis, the Vatican librarian, wrote that one of the faces was a female -- Joan the Female Pope.
Baronius also wrote that the pope at the time decreed that the statue be destroyed, but some say the local archbishop didn't want a good to statue go to waste.
"The statue was transformed," believes Cross. "I mean, literally, it was scraped off, her name and written on top of Pope Zachary."
At the Basilica in St. Peter's Square are carvings by Bernini, one of the most famous artists of the 17th century. Among the carvings are eight images of a woman wearing a papal crown, and the images seem to tell the story of a woman giving birth and a baby being born.
Medieval manuscripts tell a similar tale: Two-and-a-half years into her reign, Pope Joan was in the midst of a papal procession, a three-mile trip to the Church of the Lateran in Rome, when suddenly at a crossroads, she felt sharp pains in her stomach.
She was having contractions, the stories say. The unthinkable happened -- the pope was having a baby.
"And then, shock and horror," says Malone. "And then the story gets very confused, because some of the records say she was killed and her child was killed right on the spot. Other records say she was sent to a convent and that her son grew up and later became bishop of Ostia."
Stories vary -- some say the crowd stoned her to death, others say she was dragged from the tail of a horse -- but in most accounts, Pope Joan perished that day.
In the decades that followed, the intersection was called the Vicus Papissa -- the Street of the Female Pope -- and for more than 100 years, popes would take a detour to avoid the shameful intersection.
Polonus writes: "The Lord Pope always turns aside from the street ... because of the abhorrence of the event."
The modern Catholic Church and many scholars dismiss the story of Pope Joan as a sort of Dark Ages urban legend.
Valerie Hotchkiss, a professor of medieval studies at Southern Methodist University in Texas, says that the story of Pope Joan was actually added to Martin Polonus' manuscript after he died.
"So he didn't write it, but it was put in very soon after his death, like around 1280 to 1290," says Hotchkiss. "And everyone picks it up from Martin Polonus."
Medieval monks were like copy machines, say some scholars, simply replicating mistakes into the historical record.
"And they're picking it up from each other and changing it and embellishing it," Hotchkiss says.
Monsignor Charles Burns, the former head of the Vatican secret archives, says the story intrigued people in the Middle Ages just as it intrigues people today. "This was almost like an Agatha Christie," he says, referring to the classic mystery writer.
Burns says there is no evidence and no documentation in the secret archives that Pope Joan existed, no relic of Pope John Anglicus anywhere.
And disbelievers can explain away the other clues. The Bernini sculptures were modeled after the niece of the pope; the Vicus Papissa was named for a woman who lived in the area.
Yet even those who laugh at the story of the female pope agree that it opens a window on the history of women and sex in the Catholic Church. Women were at one time a potent and threatening force in the medieval church.
Many scholars say there were many women martyrs in that era, women who were tortured for their religious beliefs. And there were women who became saints while cross-dressing as monks.
St. Eugenia, for example, became a monk while disguised as a boy, and was so convincing she was brought to court on charges of fathering a local woman's child. She finally proved her innocence only by baring her breasts in public.
"There are over 30 saints' lives in which women dress as men for a variety of reasons, and with a variety of outcomes," says Hotchkiss, who has written about these "transvestite nuns."
Perhaps most threatening to the church were two groups of women known as beguines and mystics, who claimed they could bypass the church hierarchy and communicate directly with God.
"And they really terrified the church because they went around saying things like 'My real name is God,'" says Malone. "And so mysticism, then, gave these women ... an access to God that was parallel to the church."
These powerful women could have inspired a so-called crackdown by the church after A.D. 1000, as it consolidated its ranks and reaffirmed the rules on celibacy among its priests, a requirement that's still controversial today.
One school of thought says the story of Pope Joan was invented as a cautionary tale. The lesson to women: Don't even think about reaching for power or you will end up like her -- exposed and humiliated.
Another school argues that it was the fear of female power that led the church to essentially expunge Pope Joan from history.
But how do historians explain the enormous purple marble chair on which popes once sat as they were crowned. The chair has a strange opening, something like a toilet seat, reportedly used to check "testiculos habet" -- or whether the pope had testicles.
David Dawson Vasquez, the director of Catholic University of America's Rome program, says that the Vatican was just using the most impressive chair it had.
"Because it's elaborate, it's purple. It was the most expensive marble of Roman times, and so it was only used for the emperor," Vasquez says. "The hole is there because it was used by the imperial Romans, perhaps as a toilet, perhaps as a birthing chair. It doesn't matter if there's a hole there, because you can still sit there and be crowned."
Others say it was a symbol of the pope giving birth to the mother church. Either way, newly minted Protestants in the 1500s had a field day making fun of the chair, and so it was hidden from view.
And so the last relic in the tale of Pope Joan is withdrawn. But Pope Joan lives on in some other place, in the shadows of a Dark Ages legend that is terrifying to some and inspiring to others.