Actor Larry Hagman and actress Linda Gray ride horses as they arrive for a VIP Preview party for the Collection of Larry Hagman at Juliens Auctions in Beverly Hills, California June 1, 2011. REUTERS/Mario Anzuoni

It was one of the great moments in TV history. In the summer of 1980, Dallas was the most-watched show on the planet and the question on everyone’s lips was: ”Who shot JR?” The attempted murder of the tough-talking Texan oilman attracted 21.4million viewers in Britain and an estimated 300million worldwide. It became a pop culture “event” which remains in the top ten televised moments of all time, alongside Neil Armstrong’s first steps on the Moon.

Larry Hagman - who played JR Ewing - still shakes his head in disbelief at what he calls “the whole hoo-ha of it all”.

“I fled to England and holed myself up in a flat for six weeks, and used it as a bargaining tool for my agent to demand more money,” he says with a mischievous grin.

And did it work?

“Hell, yes. I’ve been laughing all the way to the bank ever since.” Hagman, now a sprightly 79 and in robust health since a liver transplant 16 years ago, meets me in his £3.5million Santa Monica beachfront apartment, which has sweeping views over the Pacific. He also owns a 233-acre ranch, aptly called Heaven, in the town of Ojai, some 50 miles north of Los Angeles.

He has agreed to this, his first interview since the announcement two weeks ago that Dallas will return to our screens next year in a £35million update, because - and he growls this in a way to make JR proud - “there has been so much BS written about the whole thing”.

Hagman still earns a good living in endorsement deals and autograph-signing events, and a recent auction of memorabilia netted £300,000. But he says claims that he will earn a million dollars an episode in his old role - alongside original cast members Linda Gray as JR’s long-suffering wife Sue Ellen and Patrick Duffy as his upstanding younger brother Bobby - are “utter rubbish”.

“I’ve been doing this a long time and I’ve found that people tend to believe what they want to believe, but it’s important for me to tell it how it is,” he says in a slightly grumpy fashion.

“I’m nearly 80 years old and these days with the iPad or the iPod or the i-whatever, things go round the world, then my daughter rings up to say, “Hey Dad, congrats on your million bucks a show!” I reckon if I just tell it as it is, then the truth can be out there too - if people care to read it.”

For Hagman, the return of the show that made his name - and that nearly killed him thanks to an alcohol addiction that ended with him being two weeks from death - is something he calls “a blessed event”.

He lets slip a couple of crucial facts about the new plot. Sue Ellen now runs Ewing Oil. JR, once the bombastic boss, is so depressed he might be considering ending it all. Hagman says: “I can’t give away any more. I’ll be shot. Let’s just say things have been tough for JR as they have been tough for me.”

The past couple of years have indeed been tough. His beloved wife of 57 years, Maj (pronounced My), a Swedish costume designer he met in London in 1954 during a stint in the US Air Force, is suffering from Alzheimer’s.

Hagman attempted to care for her himself, “But after two years it just got too hard,” he says.

“I love that woman but it was just a 24-hour-a-day job. It became my life. I never resented it but she’s a strong personality. I started to get the feeling she wasn’t happy and I wasn’t happy.

“I put her in a care facility and that was a disaster because she hated being around other people. She can be difficult, my Maj. So a few months ago I bought an apartment a five-minute walk from here. It is hers and she feels safe and she has 24-hour care. I still go and see her every day for lunch and more if I can.”

His eyes well up as he says: “I miss her every day. I get lonely. I have so much time on my hands. We spent our life together, we were a good team. Her Alzheimer’s hasn’t yet robbed her of the knowledge of who I am. I dread that day. She can remember things that happened 50 years ago but she can’t remember what she had for breakfast.

“It’s a cruel disease. That’s why Dallas is good for me. It made my name the first time around. Now I believe it will save me by keeping me busy and working.”

The role of JR made Hagman, a jobbing actor previously best known as the son of Broadway legend Mary Martin, a household name. Dallas ran from 1978 to 1991 and chronicled the debauched, dysfunctional lives of the Ewings.

What he calls “stuff” from the old days fills the flat: a gleaming silver JR belt buckle, a collection of JR’s ten-gallon hats above the door, pictures of Hagman and Linda Gray gumming to the camera and another of him, eyes closed, in a pool weeks after his life-saving liver transplant.

Born in Texas, he was five when his lawyer father and actress mother divorced. His mother fled to Broadway, leaving him to be raised by his grandparents.

Hagman first found fame in the Sixties TV comedy show I Dream Of Jeannie, but it was as the whiskey-swilling, womanising oilman JR in Dallas that he found superstardom.

What does he think made Dallas so beloved - and why will the new series resonate with a younger, more worldly audience?

“Dallas hit a chord back in the late Seventies and Eighties because it was the age of greed: here you have this unapologetic character who is mean and nasty and ruthless and does it all with an evil grin.

“I think people related to JR back then because we all have someone we know exactly like him. Everyone in the world knows a JR. I think it will translate to today’s audiences because greed has never gone out of fashion, nor has being a bastard. The troubles of life are the eternal troubles - does my wife love me, is my husband being faithful, do I have enough money, is my boss a pig?”

The pilot introduces fresh characters for a modern audience. Among them are John Ross Jr (Josh Henderson of Desperate Housewives) and his cousin, Bobby’s son Christopher (Jesse Metcalfe also from Desperate Housewives). They are locked in a duel over stunning Jordana Brewster.

The show will air in America on the TNT network. Filming begins in Dallas in October. The original release date of next July has been brought forward because of what Linda Gray calls “massive interest” after TV executives saw the pilot earlier this month.

But will anyone tune in?

“I wouldn’t have signed off if the script wasn’t good,” says Hagman. “The new kids are gorgeous and have good teeth but can also act. There’s more competition today.

“Back in the heyday of Dallas there were only three channels in the UK and three networks in the US. Now audiences have a multitude of things to choose from. But I would say that there isn’t that much that really grips and entertains people.

“I think Dallas will be a hit because mums and grandparents will remember sitting around as a family watching it and they’ll encourage their families to watch it. I think it’s something that just goes to the heart, the psyche, of people who were there the first time around.

“People love JR. He’s a bastard but people love him. You’re not suddenly going to get a nice JR. People want him to be mean and manipulative.

“Plus I don’t think there is anything as good on television today. I barely watch TV apart from the news. Most of it is rubbish. There’s all this reality nonsense and dross.

“I think there’s a market for a well-produced, well-written melodrama like Dallas. It’s pure entertainment.

“It’s escapism. When we started the show, Dallas was known as the city where JFK was assassinated. By the end it was known as JR’s home town.

“That was the power of TV in those days. Of course, it might not resonate in the huge way it did in the original show. But the interest so far has been huge.

“I’ve been deluged with interview requests but I am very careful who I talk to. I’m doing this interview and then that’s it until the publicity for the show.”

Hagman says walking back into the famous Southfork Ranch was “surreal”. The original ranch was owned by the Duncan family who, after the success of the show, turned it into a tourist attraction and sold it to a company which rents it out for weddings and events.

“It’s funny. It isn’t a very big mansion but when you hear that music” - he starts to hum the famous theme tune - “it evokes a nostalgia.

“The actual house is small. When I walked up to it a few weeks ago when we were filming the pilot I thought, “Well, I’m home,” and then my second thought was, “God, it’s small.” We always filmed interior shots on a studio set.”

He says the producers originally planned to film the remake in San Antonio. “But I told them it had to be Dallas. How can you not film it in Dallas? I called all my friends in town, the power players, and I got the film company a deal.”

I ask if he is hailed like a governor back in Dallas. “No, it is far bigger than that. I don’t tax people or hurt them. I am just adored. In Dallas I am king.”

Characters like Charlene Tilton’s Lucy Ewing - “the poisoned dwarf” - and Cliff Barnes, the arch-rival to JR played by Ken Kercheval, will not be returning to be fixtures in the new series, Hagman says.

“Charlene appeared in a wedding scene in the pilot but they wanted to concentrate on the main characters and introduce the new ones. I’m not sure who they will bring back but I know they couldn’t have done it without me and Linda Gray as Sue Ellen.

“I didn’t get paid a million bucks an episode but this is for a cable TV company, not a network. I understand that. To be honest, I am just happy to be working at nearly 80.”

One change Hagman has noticed since the original Dallas is the improvement in technology. “The cameras these days, the high-definition ones, they show every darn pore and wrinkle.

“I’ve never had Botox or anything and it’s far too late to start now but it did come as a shock to see every line in my face showing up so clearly.”

In person Hagman starts off rather brusque but he soon mellows. He is planning to buy a new £30,000 red Tesla sports car this weekend “to celebrate the return of JR. And heck, to celebrate still being alive”.

He proudly shows me around his flat. On one wall is a bizarre artwork containing a collection of silver staples from his liver transplant: “There were 150.”

On another is a rather garish landscape by Sir Anthony Hopkins “which I bought at a fund-raiser”.

There is a touching picture of him with Maj in London on a motorbike in 1954, the year they wed, next to another, 50 years later, on a similar bike. The couple have a son and daughter, Preston and Heidi Kristina, and five grandchildren.

Hagman says his well-publicised battle with the bottle is not something that he wants to dwell on.

One oft-repeated anecdote has it that Hagman started his day on the set with cornflakes covered in champagne, washed down with bourbon.

In 1995 he was just days from death. He was given a liver transplant from an unnamed donor. ÔI was never a fall-down drunk. I started drinking champagne in the morning and I would keep going through the day, with just a nice little buzz on.

“I had no idea that I was sick until the doc told me my liver was shot and I needed a replacement. I was never a mean drunk.”

He admits he still enjoys “the occasional glass of wine at a wedding or some other such function” but adds: “If you put that in I will have the world coming down on me”.

Hagman has already confessed to dabbling in drugs, including LSD and cannabis, in the past. Now he tells me, perhaps teasingly, that when he dies he wants to be pulped and put on a field “in which they grow marijuana and wheat and then, a few years later, bake that into a cake that my friends can eat”.

Is he kidding?

“No, I’m absolutely serious,” he says with a wink.

He spends his days, when not working, reading “30 books a week”. He plays poker with friends every Thursday night - “but the pot never goes above $40”.

One gets the feeling that he is delighted to be back playing JR, the role that defined him and which, it is likely, will see him into the sunset.

He has made a profession out of being JR. He says he can earn £250,000 a year from autograph signing and proudly shows me his own Monopoly-type money, printed on eco-friendly paper, which has his motto “Don’t Worry. Be Happy. Feel Good” printed on one side. A message on the back urges people to sign up as organ donors.

“Everywhere I go, people love me because I am JR,” says Hagman. “I have no complaints about that. It always annoys me when stars grumble about fans coming up to them in the street. I love it.

“These young stars today with all their airs and graces, they need to remember it is an honour and a privilege to make money from acting. How hard is it? When someone comes up to you and you don’t feel like being nice...well, get over it. It is part of the job.”

He has recently put his Ojai estate on the market. “I know, realistically, that Maj and I will never go back there. I want someone else to enjoy it,” he explains.

I ask Hagman which memento, of the thousands in his packed flat, he treasures most?

He walks me into his bathroom, a magnificent expanse of grey marble. Next to the sink he uses every morning to shave is a small black-and-white photograph. It is of a young man, 28 years old, with jet-black hair and a nondescript face.

He declines to give me the name but says: “That is the man who gave me my liver. I look at his face every day when I shave and I thank him for giving me this wonderful life.

“It doesn’t get more real than that.” - Daily Mail