"Barry" tells true story of James Miranda Barry (who was the first female doctor, portrayed by Rachel Weisz), who had to masquerade as a man.
In 1814, Barry graduated from Edinburgh Medical School, where she'd studied disguised as a man, and then served in the U.K. military for 45 years.
James Miranda Barry dressed as and passed for a man throughout her life, and her true sex wasn't discovered until she died.