Bronal was a figure in Klingon folklore, the head of the powerful House of Bronal, which was overthrown by Kahless in ancient times.
Bronal was a paranoid man. One day, when he heard of a powerful warrior named Gorath—who, in reality, had boasted of his accomplishments—he had the man and his family assassinated.
Bronal was defeated in combat by Kahless. (ST episode: "Klingon Fable: The Legend of Gorath")