In the course of that period, his media empire has variously decided the outcome of elections, dictated the membership of Cabinets, shaped policies on a wide range of issues and even influenced whether or not the country went to war.
But this Wednesday, the worm finally turned as the Australian media tycoon's bid to buy 100pc of BSkyB was swept away in the storm that has engulfed him in the wake of the phone-hacking scandal.
It was as if three decades of pent-up resentment had suddenly been unleashed in a torrent , as the politicians who have been forced to kow-tow to Murdoch all that time finally broke free of his yoke.
There is a certain historical irony in the fact that it was the dear old House of Commons which finally delivered the coup-de-grace to Murdoch's dreams of further media expansion.
For those of us with long memories, it seemed a fitting reward for the way in which he conned Parliament into agreeing to his takeover of The Times and the Sunday Times in 1981 by giving 'editorial guarantees' he had no intention of keeping.
These undertakings enabled the then Trade and Industry Secretary John Biffen to sidestep a reference to the then Monopolies Commission.
Within a year, Murdoch had broken every single one of them, including sacking the Times' editor and transferring the two titles into a different part of his business.
I will give two small examples from the recent past of how the influence of his empire has distorted the political life of the nation.
In 2009, the now former News International chief executive Rebekah Brooks let it be known that David Cameron's Tories would not get their support at the ensuing general election unless Dominic Grieve was replaced as Shadow Home Secretary. He duly was.
Then, last year, James Murdoch made it clear he wanted the Labour government's plans for regional news consortia scrapped. When the Coalition came in, they duly were.
These, however, are relatively trivial examples compared with, for instance, his papers' routine character assassination of certain party leaders and consultations with Tony Blair in the days prior to the invasion of Iraq.
But if Murdoch was undoubtedly the biggest loser of the week, it's not been a great seven days for Mr Cameron either.
Because it was not the Prime Minister who finally led the fightback against the Murdoch empire, but the man who wants his job - Labour leader Ed Miliband.
Mr Miliband undoubtedly took a gamble by calling a vote on the BSKyB bid – but within 48 hours every other party had followed his lead.
His reading of the public mood in this crisis has been consistently ahead of the curve and, for now at any rate, he has drawn a line under the troubles that had beset his leadership earlier in the summer.
Deputy Prime Minister Nick Clegg, too, ends the week with his position enhanced, again at Mr Cameron's expense.
It was his threat to vote with Labour on Wednesday that forced the Prime Minister into his U-turn on the BSkyB deal, potentially altering the balance of power within the Coalition in the process.
Mr Clegg has also pointedly disassociated himself with the shadow of Andy Coulson's appointment as Downing Street's director of communications that continues to hang over Mr Cameron.
"It was his appointment and his appointment alone. We did discuss it... it was something that we didn’t see eye to eye on," he said.
This is where the phone-hacking scandal starts to play into the much bigger and wider issue of the Coalition's ultimate survival.
Some Lib Dems have started to speculate that Mr Cameron may emerge from the scandal so badly damaged that they could actually bring him down.
I have argued from the start of this Coalition that the Lib Dems somehow have to find a way of getting out of it alive, and this might just be their best opportunity.
We would then not just be looking at the downfall of a media empire, but the downfall of a government.
