It's hard to read Paddy Manning's impressive biography of Lachlan Murdoch and not hear the theme song of the hit TV series Succession jangling away in the background. 

There's the ageing, but still wily, patriarch always on the search for the next big deal; siblings jetting around the world fighting for family dominance; multi-billion-dollar corporate power plays; and a once all-powerful media empire facing an uncertain future.

In The Successor, Manning tells the intriguing story of a man who at once is one of the world's most prominent media barons, but who also actively shuns the spotlight.

It is the tale of the socially progressive 20-something who was horrified at the rise of Pauline Hanson, who went on to head up the virulently right-wing Fox News.

We learn a lot about the forces that now drive Lachlan Murdoch, and what a post-Rupert News Corp might look like.

Let's start with one of Manning's big claims (and crank up that theme music again).

'Lachlan may get fired the day Rupert dies'

Lachlan Murdoch has long been seen as the heir apparent to his father's global empire.

Of Rupert Murdoch's four older children, Lachlan is the only one still actively involved in the business, as chief executive officer and executive chair of Fox Corporation, and co-chairman of News Corp.

His younger brother James Murdoch famously walked away from the company in August 2020 over his concerns about "certain editorial content".

James previously had been publicly critical of what he saw as climate change denialism in News Corp's Australian outlets.

Younger sister Elizabeth has long been out of the family business, while Lachlan's older half-sister Prudence was never really in it.

All four have an equal vote on the Murdoch Family Trust (Rupert Murdoch's two children with ex-wife Wendy Deng, Grace and Chloe, don't get a vote).

Manning writes about his belief that the "plausible scenario" after Rupert dies, is of James, Liz and Prue teaming up to roll Lachlan for control of the business, and then to run the papers and TV networks "…in a way that enhances democracies around the world …"

Manning speaks to a Wall Street analyst who has covered the Murdochs for decades "… volunteering off-the-record that it would be 'fair to assume Lachlan gets fired the day Rupert dies'".

For as long as he is alive, and Rupert Murdoch has often joked about being immortal, the media mogul has absolute control over his empire and its component parts.

Manning's revelations leave us contemplating whether all bets could be off once the 91-year-old is no longer with us.

'It was quite clear he wanted to be a decent person'

It also becomes pretty obvious reading this unauthorised biography that Lachlan Murdoch is seen to be just as, and perhaps even more, conservative than his father.

It has been quite the journey for him.

Manning gets hold of an old interview with one of Lachlan's teachers at Princeton University, Beatrice Longuenesse, who remembers him as a "poetic character".

"It was quite clear he wanted to be a decent person, and he was a decent person," she recalls.

Longuenesse tells Manning that while she still has happy memories of supervising Lachlan, his story sadly "has become very dark and gets darker by the day".

In the book she cites the "detestable" role of Fox News in making the US a more polarised country.

Fox News is undoubtedly very popular in the US, but, as Manning points out, the toxic and inflammatory commentary the network puts to air night after night has often landed Lachlan in hot water given his role as CEO.

As hosts like Tucker Carlson and Sean Hannity continually repeat the "big lie" that the 2020 presidential election was stolen, there is no sign of the network boss reining in his high-rating presenters. 

Manning does also note that the Murdoch-owned Wall Street Journal and New York Post have both denounced Donald Trump, with Rupert Murdoch himself urging conservatives to move on from the 2020 election.

The contrast with Fox News is stark.

The network has even refused to air live hearings of the congressional committee investigating the January 6 insurrection.

Manning writes that Lachlan Murdoch often seeks to downplay his responsibility for Fox News content.

But, Manning suggests, as the CEO of Fox Corporation, Lachlan Murdoch is where the buck stops, as it does with any CEO.

Rupert was saying nothing

Despite all the doubts about what lies ahead for the Murdochs, the book's epilogue reinforces the power shift already underway.

In February this year, Lachlan summoned key executives to his Los Angeles mansion for a strategy day.

Convoys of black mini-vans snaked their way down the driveway in a scene some guests joked was worthy of Succession (cue that music again).

But what happened inside was much, much more dramatic.

It was Lachlan's show from beginning to end.

He made the key speeches and gave the main presentations.

Rupert Murdoch was seated in the front row and said nothing.

One attendee told Manning the day represented a massive turning point in the family's power dynamics.

"The baton had obviously been passed and the rest of us, as a group, we all went 'OK, we missed the point the baton got passed, but it's been passed'," the attendee said.

Barring any post-Rupert sibling machinations, Lachlan Murdoch is on the cusp of becoming one of the world's most powerful media owners.

He prefers to keep a low profile, giving few interviews (he said no to Manning) and tightly controls his public appearances.

He is very much something of an enigma.

Don't forget, Lachlan infamously left the company in 2005 after clashing with the likes of then Fox News boss Roger Ailes.

But given this is the man who likely already has operational oversight of a company that controls two-thirds of the Australian newspaper market, Australians deserve to know a lot more about him.

They could learn a fair bit from The Successor.