Jay North, who played Dennis Mitchell in the original 1959 “Dennis the Menace” TV series, died Sunday after a battle with cancer, his long-time friend Laurie Jacobson confirmed in a social media post. He was 73.

“Our dear friend JAY NORTH has been fighting cancer for a number of years and this morning at noon EST, Jay passed peacefully at home,” Jacobson wrote. “As many of his fans know, he had a difficult journey in Hollywood and after…but he did not let it define his life. He had a heart as big as a mountain, loved his friends deeply. He called us frequently and ended every conversation with ‘I love you with all my heart.’ And we loved him with all of ours. A life-long friend of Jon’s, a brother to Jeanne and a dear friend to me, we will miss him terribly. He is out of pain now. His suffering is over. At last he is at peace.”

“Dennis the Menace,” based on Hank Ketcham’s comic strip of the same name, ran for 146 episodes across four seasons. The show followed North’s Dennis “the menace” Mitchell, a young troublemaker who terrorizes his aging neighbor Mr. George Wilson (Joseph Kearns) through a never-ending series of mischievous deeds. Other cast members include Herbert Anderson, Gloria Henry, Billy Booth, Sylvia Field and Gale Gordon.

After the series ended in 1963, North went on to appear in several one-off roles on TV shows like “The Man from U.N.C.L.E.,” “The Lucy Show,” “My Three Sons” and “Jericho.” He also did voice work for series like “Arabian Knights,” “Here Comes the Grumps,” “The Banana Splits Adventure Hour” and “The Pebbles and Bamm-Bamm Show.” His last starring role was in the 1974 erotic thriller “The Teacher.”

North, a Hollywood native, was born Aug. 3, 1951, and was a fan of television from a young age. He started his career acting in commercials and appearing in small roles on variety shows like “The Eddie Fisher Show” and “The Milton Berle Show.” By the time he was six years old, he had landed the starring role in “Dennis the Menace.” He later said his experiences as a child star had been abusive and advocated for the rights of young actors.