Genuinely successful dynasties are rare in any walk of life - and that's no more true than in the dirty professions of publishing and entertainment.
It's an old, old story. The father fights his way to the top using every trick in the book, not just meeting challenges head on but actively seeking them out - and while the son may add polish courtesy of an expensive education, there's always an outside chance that the grandchildren will be snobbish dilettantes who, deep down, feel nothing but contempt for the source of the family money.
Thus, in media history, for every Harmsworth dynasty there is at least one Aitken family. Max Aitken, for instance, was charming and brave (a sporting star at Oxford, though he didn't complete his degree; and a World War Two air ace with 16 enemy kills to his credit), yet it took him only slightly more than a decade to lose control of the seemingly unassailable Daily Express empire built by his father, Lord Beaverbrook.
But the lessons of history don't stop powerful men believing they can cheat the odds, do they? Who can argue, for instance, that Rupert Murdoch hasn't done justice to the newspaper empire founded by his father? And who is to argue that James Murdoch won't do a similarly outstanding job?
We could be about to find out. For, having flirted briefly with two of his siblings, Elisabeth and Lachlan, the succession spotlight has now fallen fully on James. It is widely expected that James, the youngest son of Rupert and his former wife Anna, will shortly be confirmed as the chief executive of BSkyB.
It is believed that the BSkyB board will meet on 13 November to consider its options. In order to create an opening for James, the current chief executive, Tony Ball, (successful, but now like a family retainer who has outlived his usefulness) will have to be edged aside. Meanwhile, Rupert is also expected to step down from his current role of chairman to take up the post of non-executive director. After all, it's going to be hard enough selling James' accession to the City (the share price was wobbly for a while last week, though showed signs of settling again) without triggering concerns about possible corporate governance abuses too.
This is a rather academic nicety. If there are dissenters among the other shareholders, it is likely (given what we've seen in the past) that they will choose their words carefully. As one City analyst puts it: "Titles are meaningless. By sheer force of personality, Rupert Murdoch dominates any table he sits at." No one has ever been convinced by the fatuous corporate line from Rupert Murdoch's office - that News Corp is merely a 35.4 per cent minority shareholder and Rupert therefore can't expect to run the company as a personal fiefdom. His shadow looms large.
But James will be running BSkyB on a day-to-day basis and whatever his father's influence, there will be more than enough evidence to judge Murdoch junior's abilities.
Nothing is set in stone and there are those who believe that Rupert Murdoch will be tempted to divide his riches among all his children - not just the ones he had by Anna but the ones he's continuing to have with his latest wife, Wendy Deng. But a sharing of the Rupert legacy is unlikely, others say. An empire divided is, after all, no longer an empire, neither is it home to a dynasty.
Only one of his offspring will be given real power, they say, and obviously if James does anything approaching a half-way decent job with BSkyB, he will be installed as a massive favourite to be that chosen one.
Conservatively minded commentators (especially those employed by rival newspapers) have cast sneering aspersions. They point out that James dropped out of Harvard after the first year of his visual environment studies course - a degree so rigorously demanding that it involved making puppet movies. They further point out that James once sported tattoos (presumably still does), had pierced ears and dyed his hair a less-than-fetching blond colour - and after Harvard he started a hip hop record label that lost money before being taken over by his father's business empire.
Having been drawn within the fold, James was made the head of News Corps new-media division, just in time for the bursting of the dotcom bubble.
Within months, though, he'd been promoted up and out of that debacle, heading east to run Star TV, News Corp's pan-Asian satellite TV platform.
It's at this stage in the story that the sneering usually stops - because it was under James' tenure that Star made a profit for the first time since being acquired by his father in 1995. Still, there are those in the City who say that Asia is Asia. It's hardly London.
As another City source puts it: "James is an interesting one. At least he's not like (his sister) Elisabeth who hadn't run a business before. James has been in charge at Star TV and, by all accounts, did a good job. But this is really the big test.
"You can argue that BSkyB is a bit like a utility now and that it would take a spectacular disaster to mess it up. It's true that the job doesn't need the sort of experienced operator that it did when it was going through its rocky days. But to take it to the next stage will be some achievement."
It's not difficult to find analysts in the City who are very worried about the whole business. Investors are always nervous (on those rare occasions) when a top- 20 public company falls into the hands of someone who has never run a publicly quoted company before.
In the end, though, the issue will not be so much about whether James is a master of business admin but whether he has that rare gift, the one his father has in spades - the ability "to see round corners". On the other hand, as immortality beckons, this whole inheritance business might just be held up as evidence that Rupert Murdoch's legendary clear-sightedness has finally deserted him.