tried to seize the papal throne by force around this time.
Whoever the father was, Pope Joan is a wonderful story and as irresistible for writers and film-makers today as it has been down the ages.
Lawrence Durrell wrote a novel about her, Caryl Churchill featured her in a play, Top Girls, and Scandinavian screen siren Liv Ullmann starred in a 1972 film about her.
But the question is: can the story be true? The straight answer is that it is impossible to say.
The chroniclers who recorded Joan as fact include some of the most distinguished medieval figures, including bishops, archbishops and papal chamberlains.
None delighted in the tale, but recorded it in the interests of accuracy. But they were not eyewitnesses, and were writing 200 to 300 years after the event. A fatal flaw? Well, yes and no, for many of the popes of the Dark Ages who are accepted by the Church have left no other historical record than these chronicles.
What causes Catholicism to accept these shadowy figures as real but dismiss Joan as a tall tale is the fact she was a woman.
And if she never existed, how do you explain three curiosities of Roman life that survive her? First, there is the small wayside shrine or edicola in a back street between the Colosseum and the basilica of St John Lateran that for centuries has been treated by visitors as marking the spot where Joan infamously gave birth.
The Vatican in the 17th century rebranded it with a statue of Our Lady, but it continues to draw those curious about the woman pope. And then there are the eight incongruous designs at the base of the great baldacchino, or altar cover, in the centre of St Peter’s.
The Vatican’s denials only fuel the rumours. Seven show a woman’s face, topped by a papal crown, in various stages of agony. The final one replaces the woman’s face with a baby’s. Below the face is a swollen belly and below that folds of skin that contract to create the impression of giving birth.
Are these, as most experts suggest, just a bit of mischief by the 17th-century sculptor Bernini? Or does their presence, decorating an altar that by tradition is used only by the Pope, suggest that Joan’s legend is not so distant from the heart of Catholicism?
Finally, there is the peculiar pierced chair in the Vatican Museum. A host of medieval travellers record its use in the election ceremony for popes. Before an appointment could be confirmed, the candidate had to sit in the chair, which has a large key-shaped hole cut in its seat. The youngest deacon present would kneel down and reach up and under the chair through the hole to check its occupant was a man.
Why else would the Church employ what is popularly known as the ‘ball-feeling chair’ if Joan had never existed?
This latest film version of the story, La Papessa, is based on a novel by the U.S. novelist Donna Woolfolk Cross that sold well in Germany. It has had a chequered history, with Madonna, Nicole Kidman, Cate Blanchett and Minnie Driver all having been linked with the project.
The Catholic Church has in the past been quick to condemn films that show it in a bad light – including Angels And Demons, The Da Vinci Code and The Last Temptation Of Christ. However, history has taught the Vatican that when it comes to the legend of Pope Joan, the more it denies the story, the more intrigued people become.
So far, L’Osservatore Romano, the official Vatican mouthpiece, has remained silent about this latest sighting of the English woman who has been haunting it for nigh on a millennium.
*Peter Stanford’s account of the Pope Joan legend, The She-Pope, is published in paperback by Arrow.