The history of the Roman Empire as experienced by one of its rulers.
Cast: Derek Jacobi, George Baker, Margaret Tyzack, Siân Phillips, Brian Blessed, James Faulkner
AD 54: Claudius feels that Rome should return to be a Republic but nonetheless marries his niece Agripinilla and makes her son Nero co-heir with his own, teen-aged son Britannicus. Aware of a prophecy that Nero will indeed become sole emperor Claudius encourages Britannicus to flee abroad and then return to restore the Republic but the boy refuses and he is killed by Nero.
Whilst Claudius is invading Britain Messalina is challenging the prostitute Scylla to see who can take the most partners, Messalina easily winning. She also takes the young senator Silius as her lover, forcing him to divorce his wife so that she can marry him whilst sending Claudius a divorce decree when he is away.
Claudius has ruled wisely for a year with the support of Messalina, whom he deeply loves. Convinced of her devotion, he is totally unaware that she is deceiving him.
Claudius is happily married, while the mad Caligula has been assassinated. To his astonishment, Claudius has been proclaimed emperor by the Praetorian Guard.
Caligula's erratic behaviour continues, as he makes his horse a senator and turns the palace into a brothel. Many in the Praetorian Guard grow to realise that their ruler is insane and, fearing the collapse of Rome itself, believe that something needs to be done.
Claudius has high hopes of a return to a Republic when Caligula insanely proclaims himself a god and his sister a goddess... but Rome officially accepts his divinity.
With Tiberius retired to Capri, Sejanus plans to tighten his grip on Rome and divorces his wife so he can marry Livilla. But he also has powerful enemies and his attempts to consolidate power set in motion a bloody chain of events.
Germanicus has been murdered in Antioch and his wife Agrippina is convinced Tiberius ordered the killing. Livia has discovered that Caligula helped to poison his father. While Tiberius's perversions have become notorious, his right-hand man Sejanus, commander of the Praetorian Guard, gathers more power for himself, including a marriage alliance with Claudius.
As Augustus learned of Livia's plot against Postumus, she took action which resulted in Tiberius becoming emperor. The situation in the East now threatens Tiberius's position.
The Imperial Army on the Rhine has been wiped out and Tiberius sent to avenge the defeat, followed later by Germanicus. Livia has discredited Postumus, who has been banished. Augustus has been feeling unwell, but is avoiding suspicions of poisoning by eating figs from his own garden.
Livia has engineered the downfall of Julia, who has been banished. Tiberius is recalled to Rome and is joint heir with Postumus. Poor stumbling, stuttering Claudius finds a friend in Herod, king of the Jews.
Livia, wife of Emperor Augustus plots against his daughter Julia and manages to convince him to bring her son Tiberius back from exile.
Livia, the scheming wife of Augustus, seeks to disinherit her husband's grand-children in favour of her own son Tiberius.