Pernell Roberts, best known for his roles on Bonanza and Trapper John, M.D., died Sunday in his Malibu home after a battle with cancer, his wife, Eleanor Criswell, told the Los Angeles Times. He was 81.

The Georgia-born Roberts, who served in the Marines, began his career on the stage, winning a Drama Desk award in 1955 for his performance in a production of MacBeth. He would find TV fame in 1959 as the responsible Adam Cartwright—the eldest of the Cartwright sons—on the hit Western Bonanza. Leaving the show after the sixth season—he’d feuded with the show’s producers—Roberts returned to the stage, acted in films, and guest-starred on a variety of TV series (Mission: Impossible, Marcus Welby, M.D., Hawaii Five-O). In 1979, he scored again with the medical drama Trapper John, M.D., in which he played Dr. “Trapper” John McIntyre, a character spun off from M*A*S*H. The show lasted seven seasons.