Stéphanie-Felice Poterin du Motel is known to history only for being the object of mathematician Évariste Galois's romantic desires and possibly involved in his death. She was born around 1815, the daughter of a prison doctor in France. While in prison for revolutionary activities in 1831, Galois caught cholera and was treated by du Motel's father. Galois fell in love with her during this time. They wrote letters to each other after Galois's release, but she rejected his advances.
In 1832, Galois fought a duel. His opponent was once thought to be an artillery officer named Pescheux D'Herbinville, but is now thought to have been a former friend of Galois named Ernest Armand Duchâtelet, possibly with the help of Denis Faultrier. Nobody knows exactly how du Motel was involved.
Galois is considered one of the more romantic and tragic figures among mathematicians, and a lot of people in the field have speculated as to the exact nature of the duel. Tony Rothman, physicist, speculated in his book Science à La Mode that Galois and Duchâtelet both fell in love with her while they were both in prison, and agreed to settle their dispute by fighting a duel in which it was unknown which of their guns would be loaded. Mario Livio, astrophysicist and author of The Equation That Couldn't Be Solved, has suggested that Galois offended du Motel in some way. In that scenario, her lover, Duchâtelet, and her mother's second husband, Faultrier, defended her by challenging Galois to a duel. Others have suggested that du Motel conspired with someone else in order to have Galois killed. Whatever the cause of the dispute, Galois died from complications of wounds sustained in the duel.
After reading many descriptions of Galois as arrogant and rash in character, I'm inclined to believe either Rothman's or Livio's interpretations of events. He could have easily gotten into a duel with a friend over a woman they both loved, and he could have also gotten himself into trouble with her lover by pursuing her once she made it clear she was not interested. Galois himself apparently wrote that the duel was a matter of honor. This long after the fact, it is difficult to know what really happened.
Because historians have mostly focused on the life and accomplishments of Galois, there is little other information available about the rest of Stéphanie-Felice du Motel's life. Her father died and her mother married Denis Faultrier. What became of Stéphanie herself, her reasons for rejecting Galois, and her precise role in the duel, remain unknown.
Sources:
Darling, David. The Encyclopedia of Astronomy Astrobiology and Spaceflight: Galois, Évariste (1811-1832). http://www.daviddarling.info/encyclopedia/G/Galois.html. The Worlds of David Darling. Accessed June 10, 2007.
Kaufmann, Ralph M. Evariste Galois (1811-1832). http://www.math.uconn.edu/~kaufmann/math242Wf04/Lecture24n.ppt. University of Connecticut Department of Mathematics. Accessed June 10, 2007.
Livio, Mario. The Equation That Couldn't Be Solved: How Mathematical Genius Discovered the Language of Symmetry. New York: Simon & Schuster. 2006.
Rees, Mary. Evariste Galois (1811-1832). http://www.liv.ac.uk/~maryrees/homepagemath302/m302_9_3_07vital.pdf. University of Liverpool Department of Mathematical Sciences. Accessed June 10, 2007.
Rothman, Tony. Science à La Mode: Physical Fashions and Fictions. Princeton: Princeton University Press. 1991.
Peterson, Ivars. Math Trek: The Galois Story. http://www.sciencenews.org/articles/20060225/mathtrek.asp. Science News online. Accessed June 10, 2007.
Tseng, Jimmy. ISCID Encyclopedia of Science and Philosophy: Evariste Galois. http://www.iscid.org/encyclopedia/Evariste_Galois. International Society for Complexity, Information and Design. Accessed June 10, 2007.