Ali Baba is a character from the folk tale Ali Baba and the Forty Thieves. Ali Baba is a poor woodcutter who discovers the secret of a thieves' den, entered with the phrase "Open Sesame". The thieves learn this and try to kill Ali Baba, but Ali Baba's faithful slave-girl foils their plots. Ali Baba gives his son to her in marriage and keeps the secret of the treasure.This story is included in many versions of the One Thousand and One Nights. It is one of the most familiar of the "Arabian Nights" tales.