Cadmus. The hero who, having slain the dragon which guarded the fountain of Dirce in Boeotia, sowed the teeth of the monster. Then a number of armed men sprang up and surrounded Cadmus with intent to kill him. By the counsel of Minerva, he threw a precious stone among the armed men, who, striving for it, killed one another. According to tradition, Cadmus introduced the use of letters into Greece - the alphabet, as introduced by him, consisting of sixteen letters.