Known as the Lioness of Brittany, Jeanne de Clisson turned to piracy to avenge her husband, who the French king had had executed for treason. Olivier de Clisson was her third of four husbands, the first having died and the second marriage having been annulled. Together, they had ruled part of Brittany, but following the Breton War of Succession, he was accused of not defending his city vigorously enough; he was beheaded in 1343. Jeanne was then charged, because she had tried to bribe a sergeant to free her husband. Thanks to powerful friends, she avoided the banishment and confiscation of property that she was sentenced with.
She then swore vengeance upon the French King Philip VI and the duke who had accused her husband of treason. She sold her estates, raised a fighting force of 400 loyal men and started attacking. One of her early targets was a castle at Touffou, where the officer in charge recognised her and let her in, at which point her men massacred the entire garrison, save one person. This was a precursor to her practice of leaving only one or a few sailors alive when she attacked ships, to carry word to the King of France.
With the help of the English king and Breton sympathisers, she started building her Black Fleet, outfitting three warships painted black, with red sails. She named her flagship My Revenge. She started attacking ships in the Bay of Biscay but soon escalated to hunting down French commerce ships in the English Channel. She is also said to have attacked villages along the Norman coast.
At one point, the French were able to sink her flagship and Jeanne and two of her sons were adrift for five days, with her son Guillaume dying of exposure while Jeanne and her other son Olivier were eventually rescued, and resumed their piracy. All told, she was active for over a decade in her 40s and 50s, from around 1343 to 1356.
Jeanne is sometimes referred to as a privateer, meaning her piracy was sanctioned by the English crown, which was a common practice at the time. Although no official documentation of this exists, she did work with the English, including using her ships to supply their forces.
Jeanne remarried for the fourth and final time in the 1350s, to one of the English king’s deputies, and later settled at the Castle of Hennebont, on the Brittany coast. Husband and wife died a few weeks apart in 1359, when Jeanne was 59.