Hagman, a native of Fort Worth, Texas, was an established TV and movie actor in the U.S. when he was catapulted to worldwide fame after landing the role of the treacherous businessman in 1978.
And as he prepares to re-visit his most famous character when Dallas re-launches next year (12), WENN has put together 10 fascinating facts about the star to say - Happy Birthday, Larry!
- Hagman's mother was the late, legendary actress Mary Martin. She bestowed upon him the childhood nickname Lukey.
- Before finding fame, he served in the U.S. Air Force, where he honed his stagecraft by spending hours entertaining his fellow troops.
- Hagman broke his collar bone in a childhood accident.
- During his time on Dallas, Hagman's portrayal of J.R. Ewing was so central to the show's popularity, he re-negotiated his contract to earn $100,000 (£62,500) per episode - making him one of the highest-paid actors on U.S. TV.
- A committed anti-smoker, Hagman served as chairman of the American Cancer Society's Great American Smokeout.
- He underwent a liver transplant in 1995 after years of heavy boozing left it ravaged. He has since become an outspoken campaigner for liver donation, and wears a ring made from gallstones removed from the organ during the transplant.
- He was the only actor to star in all 357 episodes of Dallas – although for several episodes during the infamous 'Who Shot J.R.' saga, Hagman's face was not shown as the character recovered in a hospital bed. He still holds the record for the greatest number of consecutive appearances by a lead actor in a 60-minute primetime drama.
- Hagman became close friends with The Who wildman Keith Moon when the drummer lived in Los Angeles in the 1970s, and the hard-drinking pair would frequently party together.
- He owns a ranch in Ojai, California, and a home in Sundsvall, Sweden – the hometown of his Swedish wife, Maj.
- He has a vast collection of hats and canes.