In 180 A.D., General Maximus leads the Roman
Army to a decisive victory over the Germanic barbarians near Vindobona, bringing an end to
an extended war and earning the admiration of the ageing Emperor Aurelius. Maximus intends
to return home after the victory. However, Emperor Aurelius tells Maximus that his son,
Commodus, is unfit to rule and states his wish for Maximus to replace him as regent and
eventually return power to the Roman Senate. Aurelius allows Maximus time to think before
informing Commodus. Angered by this decision, in a frenzy of jealousy, Commodus
secretly murders his father. Proclaiming himself the new emperor,
Commodus demands Maximus' loyalty, but Maximus, realizing Commodus' role in the
Emperor's death, refuses. Commodus orders Maximus' execution and sends Praetorian Guards,
led by Quintus, to assassinate Maximus' wife and son. Maximus narrowly avoids execution by killing
his captors and rides to his home near Turgalium, only to find the burnt and crucified bodies
of his family in the ruins of his villa. After burying his wife and son, Maximus collapses on
their graves due to injuries and exhaustion. Slave traders discover Maximus and take
him to Zuccabar, in the Roman province of Mauretania Caesariensis, where he is bought
by Proximo, the head of a local gladiator school. Distraught after the death of
his family and betrayal by his empire, Maximus initially refuses to fight. However,
as he defends himself in the arena, his impressive combat skills win over the audience.
Maximus befriends Hagen, a Germanic barbarian, and Juba, a Numidian hunter. Juba becomes
a close friend and confidant to Maximus, and the two often speak about the afterlife
and Maximus' hope to reunite with his family. In Rome, Commodus organises 150 days of
gladiatorial games to honour his father and gain the favour of the Roman public.
Proximo's group of gladiators is hired to participate. Hearing this, Proximo confides
to Maximus that he was once a gladiator freed by Aurelius and encourages him to win
the crowd to secure his own freedom. Wearing a masked helmet, Maximus makes his debut
in the arena as a Carthaginian in a re-enactment of the Battle of Zama. Maximus leads his
side to victory against a stronger force, winning the crowd's support. Commodus and his
young nephew, Lucius, enter the Colosseum to congratulate the victors. Seeing Lucius,
Maximus refrains from attacking Commodus, who demands he reveal his identity. Maximus
removes his helmet and declares his intent for vengeance. Commodus, unable to kill
Maximus due to the crowd's overwhelming approval, leaves the arena sulking. That
evening, Maximus is visited by Lucilla, his former lover and Commodus's sister.
Distrusting her, Maximus refuses her help. As the games advance, Commodus sets up a
duel between Maximus and Tigris of Gaul, Rome's only undefeated gladiator, in an arena
surrounded by chained tigers whose handlers are instructed to target Maximus. After an intense
fight, Maximus narrowly conquers Tigris and awaits Commodus' decision on Tigris' destiny. Commodus
signs for death, but Maximus spares Tigris, defying the Emperor and gaining the crowd's
approval. Commodus becomes more irritated with his failure to kill Maximus or suppress his
growing popularity, as his own support declines. After the fight, Maximus meets his old
servant Cicero, who assures him that his army is still loyal and stationed near
the port of Ostia. Maximus devises a plan with Lucilla and Senator Gracchus to reunite
his army and depose Commodus. Lucilla meets Maximus at night to coordinate his escape,
and the two share a kiss. However, Commodus suspects his sister's deceit and threatens
her son, forcing her to reveal the scheme. The Praetorian soldiers quickly storm Proximo's
gladiator barracks. Proximo and his men sacrifice themselves to enable Maximus' escape. During
the siege, Hagen and Proximo are killed, while Juba and the other survivors are
imprisoned. Maximus gets to the city walls, only to witness Cicero's execution and be
ambushed by a group of Praetorian soldiers. Commodus demands that Lucilla provide him with
an heir. To win back public favor, he personally challenges Maximus to a duel in the Colosseum.
Knowing that Maximus is the superior fighter, Commodus stabs him with a stiletto and
has the wound concealed under Maximus' armor. During the fight, they exchange
blows until Maximus eventually disarms Commodus. Quintus and the Praetorians refuse
to help Commodus. When Maximus drops his sword, Commodus draws a concealed stiletto
and continues the attack. Maximus then overpowers Commodus and
kills him with his own stiletto. As Commodus collapses in the quiet Colosseum,
a dying Maximus begins to imagine his wife and children in the afterlife. Maximus then orders
the release of Proximo's gladiators and the reinstatement of Senator Gracchus, tasked
with returning Rome to Senate-led rule. Maximus falls unconscious, and Lucilla
rushes to his side. Maximus dies peacefully, and joins his family in the afterlife. Senator
Gracchus and Proximo's gladiators solemnly carry his body out of the Colosseum. Later that night, a
newly freed Juba buries Maximus' two small statues of his wife and children in the Colosseum,
saying that one day he will join them as well.