Tyrannus is the bodyguard to Julius Caesar but,on the fatal day when the conspirators plan to murder Caesar,Tyrannus has been lured away by a gang in league with the assassins who have kidnapped his son Piso. Tyrannus manages to save his son but by the time he returns to the senate Caesar has been murdered,secretly leaving a will that names his adoptive nephew Octavian as his heir.

Atia, the sister of Caesar and mother of Octavian,is coerced by the senate to reveal the contents of the late general's will - which discloses the fact that he has named Octavian as his successor. This makes him a target for Brutus and Cassius and the other conspirators but Mark Antony is also disappointed by the news. Tyrannus sees Octavian as his responsibility and the pair agree to flee Rome.

Disguised as simple slaves, Tyrannus and Octavian look for allies in the countryside but they are captured at General Magonius's farm and taken to Arkham, where men are forced to train as gladiators. As an ex-gladiator himself Tyrannus is able to acquit himself well and to overcome Magonius, inspiring the other imprisoned men to revolt and escape. He and Octavian see a group of horsemen coming towards them but are relieved to find that they are led by Mark Antony.

Antony takes Octavian and Tyrannus to his villa though Tyrannus is suspicious of their host,especially as he tries to separate him from Octavian. Antony invites a group of citizens loyal to Julius Caesar to the villa and Octavian outlines his plan of a Roman empire to them though reception is mixed. Tyrannus is still sceptical but leaves for Cyprus to check on the welfare of his family. Antony meanwhile persuades Octavian that they should sign a pact wherein if anything happens to the one all his power is bequeathed to the other. Too late Octavian realises that he has fallen into a trap and is at Antony's mercy.

Antony has Octavian bitten by a snake and left to die. He claims the murderers were consuls,whom he has summarily executed whilst banishing Brutus and Cassius. Former soldier Agrippa,charged with disposing of Octavian's body,takes him to vestal virgin Camane,who heals him. Tyrannus discovers that his wife is dead and his son is being raised by the kindly Marius who can give him a better life,so he returns to the gladiatorial ring,where Antony recognizes and imprisons him. Learning that Octavian is not dead Antony sends out more assassins but Agrippa and Octavian escape.

Octavius relinquishes the beautiful Vestal Virgin, Camane, so that he can devote himself to being the Emperor of Rome. Tyrannus, the former slave and gladiator, joins Octavius' forces in their fight against the power-hungry Marc Antony, with the fate of Rome and the western world hanging in the balance.