One of the best doctors in the British empire in the 1800s was a woman. She was the first woman to graduated from a British medical school and rose to the second most senior medical position in the British Army. But no one knew her true gender.

Margaret Ann Bulkley was a smart woman by any standards. She was, however, a woman in a society that didn’t believe in women. Still, her intelligence was impossible to ignore, and she was encouraged by an artist named James Barry and the Venezuelan revolutionary leader Francisco Miranda to disguise herself and attend the medical school at the University of Edinburgh. After, Miranda told her, she could move to Venezuela and practice freely as a woman.

At age 20, in 1809, Bulkley donned mens clothing and took the name of her family friend: James Barry. By 1812, she had graduated and was ready for an illustrious career. Yet she couldn’t flee to Venezuela and practice freely, so she kept her disguise and joined the British Army.

People always thought she was weird, but never that she was a woman. Atlas Obscura writes that she was a vegetarian, kept a goat for goat milk, had a small dog with her, and never went anywhere without her servant Danzer. She was also a lady killer and always seen with the finest women.

Her deception wasn’t publicly uncovered until she died. The army, upset that they were fooled, put a 100-year embargo on everything involving Bulkley. It wasn’t until 1958 that her story was once again uncovered by the scholar Isobel Rae.

Margaret Ann Bulkley is a name you don’t want to forget.