The Tv legend passed away on Friday (23Nov12) and now his only son Preston has spoken to news show Entertainment Tonight about the actor's final years.
He says, "Doing Dallas is what kept him alive as long as he did. He just loved coming to work every single day... It wasn't about the money, it wasn't about the fame, it was about him acting. That's what he did."
Preston admits family and friends were prepared for Hagman's death, but he admits it came "a lot sooner than we thought".
And he's glad his father's Dallas co-stars Linda Gray and Patrick Duffy were with Hagman for his final hours: "Those three were the Three Musketeers. Patrick was so funny; he came in and looked at dad and said, 'Larry, you're always taking the spotlight!'
"And Linda handled it with grace and poise. She's just part of our family."
Hagman died as a result of cancer-related complications.