The series opens with Augustus, the first Emperor of Rome, attempting to find an heir, and his wife, Livia, plotting to elevate her son Tiberius to this position.

An expert poisoner, Livia uses the covert assassination and betrayal of her rivals to achieve her aims, beginning with the death in 22 BC of Marcellus.

The plotting, double-crossing and murder continue for many decades, through the reign of Tiberius, the political conspiracy of his Praetorian Prefect Sejanus and the depraved rule of the lunatic emperor Caligula, culminating in the accidental rise to power of his uncle Claudius.

The "slightly nastier version" of the episode's closing (a scene that used "makeup on her belly") was allegedly shown twice in 1976, but is now lost since the BBC no longer has a copy of it.

Pulman noted that the original script for the episode ended with "a long shot showing the butchered woman hanging on a chariot".

During its original airing in 1976, the BBC estimated that I, Claudius had an average audience of 2.5 million viewers per episode, based on rating surveys.

The website's consensus reads: "Marrying a trove of terrific actors at their peak with a masterful script that draws from irresistibly juicy source material, I, Claudius transcends its paltry production values to become a gold standard for historical dramas.

[15][16] The Daily Telegraph opined that the "...lust for power, devious plotting and mesmerising machinations" displayed in the show foreshadowed later series like The Sopranos, Game of Thrones, and House of Cards.

This in turn expanded the palette and quality of network drama and, most recently, persuaded AMC executives to begin original programming.

[18] However, criticism is sometimes levelled at the series over its relatively primitive production quality compared to modern TV drama,[19] with Charlotte Higgins of The Guardian writing that "it's hard to suppress a giggle in the opening scene at Derek Jacobi's make-up and stringy wig.