The names of the Three Musketeers are Athos, Porthos and Aramis. The main character of the novel, however, is d'Artagnan, a poor, young adventurer who leaves his home to join the famous Musketeers of the Guard.
While originally rough around the edges and impossible to teach, d'Artagnan eventually settles into his role as the fourth musketeer. It is he who coined the phrase, "All for one, one for all!" which celebrates the brotherhood of the musketeers. Athos serves as the patriarch of the musketeers, as he is the oldest and seemingly least prone to flights of capricious behavior. Aramis is young, extremely ambitious and deeply devoted to religion. Porthos revels in fine clothing and fine women. Being gullible, but open and honest, he is a glutton for punishment.