Larry Hagman was born in 1931 in Fort Worth, Texas.   He was son of the major Broadway star Mary Martin.   He began his career on the stage and appeared in London’s West End in the chorus of “South Pacific” which starred his mother in 1951.   He made his film debut in 1963 in “Ensign Pulver” which starred Robert Walker Jnr and Millie Perkins.   In 1965 he starred with Barbara Eden in the TV series “I Dream of Jeannie” which ran for five years.   In 1978 he achieved worldwide fame with his role as ‘J.R. Ewing’ in “Dallas” which ran until 1991.   In 2011 he resumed filiming of his role in the new series of “Dallas” but died in November 2012 aged 81.

Ronald Bergan’s “Guardian” obituary:

On 21 November 1980, 83 million people in the US and 24 million in the UK watched the TV show Dallas to see who had shot the villainous JR Ewing. While working late at the office, the boss of Ewing Oil was suddenly fired on by an unseen assailant. Who shot JR, and would he survive?

Any character who had ever come into contact with the oleaginousTexas oilman had good reason to do away with him, but there was no way he could really have been killed off. If JR had died, then the series would have died, because JR was Dallas – and Larry Hagman, who has died aged 81 after suffering from throat cancer, was JR.

Other actors were at times replaced in their roles, but Hagman was irreplaceable. Nevertheless, just in case, Hagman quickly renegotiated his contract with Lorimar Studios just after the episode in which he was shot, securing an annual salary of around $1m. JR thus survived the attempt on his life, and continued his scheming ways for another 10 seasons.

One should not underestimate Hagman’s achievement in becoming the man the whole world loved to hate, the focal character of this progressively preposterous soap opera. With his bug eyes, smarmy grin and dicey hairpiece, Hagman generated a certain lethal charm as he went about betraying trusts and manipulating innocent people. He was Machiavelli in a Stetson, the evil face of capitalism – though, according to Hagman, “JR has lost Ewing Oil more than $16m.”

Hagman, nominated twice for an Emmy award, though he never won, was the only member of the cast to be in all 357 episodes of Dallas from 1978 to 1991. Ironically, nothing in his previous acting career had indicated Hagman was other than a competent light-comedy actor whose fame would be strictly limited, despite being the son of Mary Martin, known as the “first lady of the Broadway musical”.

Born in Fort Worth, Texas, he was brought up for a while by his grandmother after his parents divorced when he was five; he was then shunted between his mother and his district attorney father, Benjamin Hagman, and was moved around various private schools and psychotherapists.

At the age of 20, Hagman moved to London as a member of the chorus of Rodgers and Hammerstein’s South Pacific, which starred his mother as Nellie Forbush, the role she created on Broadway. Hagman and Sean Connery, a year older, were among the shirtless sailors who sang There Is Nothing Like a Dame.

After a year at Drury Lane, Hagman joined the US air force. Four years later he resumed his acting career in earnest, getting roles on television and in films. Hagman made little impression in his first Hollywood movies, as servicemen in Joshua Logan’s Ensign Pulver (1964) and in Otto Preminger’s In Harm’s Way (1965). However, he was very good playing weak men in two Sidney Lumet films: as the US president’s nervous Russian interpreter in the nuclear scare story Fail-Safe (1964), and as Joanna Pettet’s playwright husband with a penchant for wine and women in The Group (1966).

In Harry and Tonto (1974), he was the selfish, whining son of retired teacher Art Carney. He hammed it up as an incompetent, gung-ho American colonel in The Eagle Has Landed (1976), and as a caricatured Hollywood studio executive in Blake Edwards’s S.O.B. (1981).

But it was television that was the foundation of his career. Hagman had scores of TV appearances. His first real success came in I Dream of Jeannie (1965-70), in which he played a befuddled bachelor astronaut who finds himself master of a glamorous, 2,000-year-old genie (Barbara Eden). Continuing to display a deft light touch, Hagman went on to appear in other mildly amusing sitcoms.

Then came the long-running Dallas, which Variety initially called “a limited series with a limited future”. Robert Foxworth was originally cast as JR, but he wanted the role softened too much for the producer’s taste, and Hagman was the perspicacious second choice.

Hagman differed from JR in most aspects, being amiable and modest, though his liking for practical jokes and dressing up in different guises, such as an English bobby or French foreign legionnaire, gained him the nickname “Wacky Larry” and “The Mad Monk of Malibu”. He was, like JR, a heavy drinker, which led to his developing cirrhosis of the liver; he had a transplant that saved his life. Thereafter, Hagman was active in several organisations that advocated organ donation and transplantation. A passionate non-smoker, he also served as the chairperson of the American Cancer Society’s Great American Smokeout, from 1981 to 1992.

In 1996, Hagman reprised his infamous alter ego in a TV special called JR Returns, in which the dysfunctional Ewing family is reunited. Then, acting against type, he showed his range as a benevolent judge in Orleans (1997). Among Hagman’s few later feature films was Mike Nichols’s Primary Colors (1998), in which Hagman was convincing as a populist, plain-speaking Florida governor. Hagman himself, a member of the Peace and Freedom party, once described fellow Texan George Bush as “a sad figure, not too well educated, who doesn’t get out of America much. He’s leading the country towards fascism.”

In recent years, Hagman became a prominent campaigner for alternative energy, transforming his California home into one of the world’s biggest solar-powered estates. He revelled in the paradox of TV’s most famous oil man driving an electric car, and his disgust with the Deepwater Horizon oil spill led him to agree to star as JR in a SolarWorld TV advert, in which he parodied vice-presidential candidate Sarah Palin’s use of the phrase “Drill, baby, drill” with the pro-solar slogan “Shine, baby, shine”.

Though he appeared in a couple of 2011 episodes of Desperate Housewives, Hagman largely retired from acting. Nonetheless, earlier this year he joined co-stars Linda Gray and Patrick Duffy in a new 10-episode season of Dallas, adding a further generation to the troubled family and its business.

Hagman married his wife, Maj Axelsson, in 1954. She survives him, as do their son and daughter.

The above “Guardian” obituary can also be accessed online here.

• Larry Martin Hagman, actor, born 21 September 1931; died 23 November 2012