J.R. Ewing was a business cheat, faithless husband and bottomless well of corruption. Yet with his sparkling grin, Larry Hagman masterfully created the charmingly loathsome oil baron on television’s long-running and hugely successful nighttime soap, “Dallas.”

Although he first gained fame as nice guy Capt. Tony Nelson on the fluffy 1965-70 NBC comedy “I Dream of Jeannie,” Hagman earned his greatest stardom with J.R. The CBS serial drama about the Ewing family and those in their orbit aired from April 1978 to May 1991, and broke viewing records with its “Who shot J.R.?” 1980 cliffhanger that left unclear if Hagman’s character was dead.

The actor, who returned as J.R. in a new edition of “Dallas” this year, had a long history of health problems and died Friday due to complications from his battle with cancer, his family said.

“Larry was back in his beloved hometown of Dallas, re-enacting the iconic role he loved the most. Larry’s family and closest friends had joined him in Dallas for the Thanksgiving holiday,” the family said in a statement.

The 81-year-old actor was surrounded by friends and family before he died.

Hagman also starred in two short-lived sitcoms, “The Good Life” (NBC, 1971-72) and “Here We Go Again” (ABC, 1973). His film work included well-regarded performances in “The Group,” “Harry and Tonto” and “Primary Colors.”

But it was Hagman’s masterful portrayal of J.R. that brought him the most fame. And the “Who shot J.R.?” story twist fueled international speculation and millions of dollars in betting-parlor wagers. It also helped give the series a place in ratings history.

When the answer was revealed in a November 1980 episode, an average 41 million U.S. viewers tuned in to make “Dallas” one of the most-watched entertainment shows of all time, trailing only the “MASH” finale in 1983 with 50 million viewers.