New Scientist has a very interesting article on Dr. James Barry, a pioneering military surgeon and Inspector General of Military Hospitals in Canada in the early 1800s. Barry was medical reformer who fought for better food, sanitation, and proper medical care for soldiers, civilians, prisoners and lepers (He once won a duel to get a leper colony built.)
Funny thing was: there was no such man as Dr. James Barry - "he" was actually a "she" and her name was Margaret Ann Bulkley:
The flaw in the scheme was that no British medical school admitted women. If Margaret was to qualify as a doctor, she would have to masquerade as a boy for three whole years.
The disappearance of Margaret Bulkley and the appearance of a young medical student called James Barry was carefully orchestrated. The Bulkleys were unknown in Scotland, so they planned to establish themselves there as aunt and nephew. Du Preez discovered that they traveled to Edinburgh by sea, rather than stagecoach. Newly enrolled at university, the freshly minted "James Barry" wrote to Reardon: "It was very usefull for Mrs Bulkley (my aunt) to have a Gentleman to take care of her on Board Ship and to have one in a strange country." This indicates precisely when the metamorphosis of Margaret took place, says du Preez. She must have had to board the ship already dressed as a boy, or risk shipboard rumours following them to Edinburgh.
To protect Margaret's secret, the pair cut themselves off from friends and family. Only the conspirators knew who they were and where they were. From now on, Margaret kept herself to herself, always wore an overcoat and lied about her age to avoid questions about her smooth chin and high voice.