Emperor Marcus decides to appoint the trusted general Maximus as his successor to the throne. This angers Commodus, Marcus' son, who kills his father to seize the throne and then plots against Maximus' family. Maximus himself is turned into a slave, forced to participate in gladiatorial competitions... Eventually, Maximus returns to Rome and seeks revenge for his family... Maximus' life changes from then on, from a courageous general to a slave who must endure many challenges...