The mystery of the pioneering British Army surgeon who successfully fooled Victorian society into thinking she was a man throughout her extraordinary life has finally been solved.
Historians have been kept guessing over claims Dr James Barry, Inspector General of Military Hospitals, was in fact a woman for more than 140 years.
Now previously unknown letters, highlighted in this week's New Scientist, have proved the diminutive physician who fought for better conditions for troops, shot a man in a duel and reached the top of "his" profession began life as the daughter of a grocer from Cork.
The scandal that shook the Victorian military establishment began when Dr Barry fell victim to the dysentery epidemic that swept London in the summer of 1865.
Only after Dr Barry's remains lay in Kensal Green Cemetery did Sophia Bishop, a maid at his lodgings who prepared the body for burial, make the startling claim he was in fact a she.
If Bishop was telling the truth, a woman had posed as a man to become the first female medical graduate in Britain, fooled the army into employing her and then kept her sex secret for half a century.
Appalled by the idea, army officials locked away Dr Barry's service records for almost a hundred years and hoped the story would go away.
With only the maid's word to go on and no post mortem, the story caused endless speculation, with some contemporaries claiming to have known all along, and others arguing Dr Barry was a hermaphrodite.
In the 1950s historian Isobel Rae gained access to army records and concluded Dr Barry was a niece of James Barry, the celebrated Irish artist and professor of painting at London's Royal Academy.
However, with no proof the debate has refused to go away. South African urologist Dr Michael du Preez first heard the story as a boy in Cape Town, where Dr Barry had introduced sweeping health reforms while he was as assistant surgeon to the garrison there.
He had fought for better food, sanitation and proper medical care for prisoners and lepers, as well as soldiers and their families, as well as becoming the first British surgeon to perform a successful Caesarean section in 1826.
He also earned notoriety for his outspoken views which provoked a duel with pistols, and for his intimate relationship with the Governor, Lord Charles Somerset, which resulted in a libel action after the pair were accused of homosexuality.
When Dr du Preez retired in 2001, he set about gathering evidence to solve the mystery of Dr Barry once and for all. Hidden in a large collection of papers relating to James Barry he discovered documents that leave no doubt that Dr Barry began life in Ireland as Margaret Ann Bulkley, daughter of Jeremiah and Mary-Ann, sister of the famous Irish artist.
They reveal a conspiracy between Margaret's mother and some of her uncle's influential, liberal-minded friends to get her through medical school.
Key evidence came from around two dozen letters, some written by Margaret as a teenager and others by Barry the student doctor.
Alison Reboul, a document analysis expert with the Forensic Science Service, has concluded they were written by the same person. Another newly-discovered letter was written by Barry to the family solicitor Daniel Reardon on "his" arrival in Edinburgh to study medicine in 1809.
Although the letter was signed 'James Barry', Reardon had written on the outside 'Miss Bulkley, 14th December’. "Reardon was a meticulous man," said du Preez.
"On the outside of all the letters he received he wrote the date and the name of the sender. You can't get much more conclusive than that."