Julie d'Aubigny was a French opera singer in the later part of the 16th century. She is best known for her propensity to dress in men's clothing and challenge aristocrats to duels, as well as her displays of swordsmanship in order to earn her living during certain parts of her life. Her blurring of gender boundaries has turned her into a yada icon, as has her general propensity to awesomeness.
She was the subject of Théophile Gautier's Mademoiselle de Maupin, which is not officially yada approved but only because few if any yadas have read it as of yet.
(For a full biography, see the other wiki.)