There comes a moment in The Borgias when our hero (as far as the term can apply in Borgias land), Rodrigo, who is a holy man (well, as far as the term can apply in Borgias land), is taking confession from an unhappy young wife, destined soon to become his lover.

Having divested her of her sins, he delivers penance:

“Flagellate your naked body, twice nightly.”

“With knotted cord, your holiness?”

“Cord of silk will suffice.” (A delicious, infinitesimal pause, long enough to let the image register.) “To destroy the beauty the Lord has granted you would be to compound your sin.”

To get something of the full gist, it pays to know that Rodrigo, big Papa of the Borgia brood, known to close friends as His Holiness Pope Alexander VI, is played by Jeremy Irons, wielding his voice like an oak-smoked bassoon he’s been keeping soaked in Courvoisier 21 for just such an occasion.

It’s been a while since Irons has dripped his brand of polite toxicity at the centre of a drama, but if you had any thoughts that his reign as king of gaunt, gentle, utterly crazy but elegant perversion might have ended, this is the show to put you right. The Borgias may be about many things – power, corruption, sin, blood, murder, flesh, lust, family, lust after other members of your family, faith, interesting headgear – but, for this viewer, finally, it’s all about the chance to watch Jeremy Irons doing finicky, evil, delicate, mad, sallow Jeremy Irons stuff, while dressed as a pope.

Indeed, The Borgias – which wouldn’t exist without the juicy ham, rich cheese and British actors template The Tudors laid down for big-budget 21st-century historical drama – is very much the series I wanted The Tudors to be, in that I always found Sam Neill’s pimped-up Cardinal Wolsey far more interesting than Jonathan Rhys Meyers’s hewn-from-rubber Henry VIII.

The Borgias launches with a double bill, and the death of innocence. Or, to be precise, the death of Pope Innocent VIII. It’s 1492 and corrupt Cardinal Rodrigo, a Spanish outsider in Rome, is plotting to get his head in the mitre. In the shadows lurks his family, the children not-so-secretly fathered with his dark-eyed mistress (Joanne Whalley – another reason this scores over The Tudors and, indeed, most other programmes with no Joanne Whalley action), including little daughter, Lucrezia, soon to be big in poisoning. Lucrezia, who is 12, is played from the first by Holliday Grainger, who is 24, just to amp up the not-quite-right feeling.

Throw in the unfailingly unsettling Sean Harris as a gently spoken, sad-eyed mass murdering holy assassin who wants whipped, and you begin to get an idea. This may not be history as it really happened. But it’s history as you want to watch on a Saturday night.

Many are intrigued by the idea of lust, crime and guilt as played out against the rituals of Roman Catholicism in the time of the Borgias – but it takes someone with Irish Catholic blood to really lay into it. Such is The Borgias’s creator, writer-director Neil Jordan, best known for films like Mona Lisa and The Crying Game. Jordan, who brings a painterly touch to the opening episode, plans the show to last four series: “In the first season, I felt it was my job to very carefully plot out the historical context,” he told The Hollywood Reporter. “Now, I’m writing the second, I can get much more down and dirty much more quickly. It becomes much more drenched in blood ...” Promises, promises.