Évariste Galois, a major contributor to abstract algebra, had an interesting life. He had participated in the French Revolution of 1830; worked on mathematics while in jail; and died when he was 20 years old as a result of being shot in the abdomen in a duel.

https://www.youtube.com/watch?v=pdYe4BKcm74 (Galois Theory - Math History)

https://en.wikipedia.org/wiki/%C3%89variste_Galois