The Three Musketeers is a novel by Alexandre Dumas. It recounts the adventures of a young man named d'Artagnan after he leaves home to become a musketeer. D'Artagnan is not one of the musketeers of the title; those are his friends Athos, Porthos, and Aramis—inseparable friends who live by the motto, "One for all, and all for one".