Leslie Charleson, whose Dr. Monica Quartermaine, the longest-reigning character on “General Hospital,” has died. She was 79.

Charleson died as a result of a long illness, said ABC News, which airs the long-running soap opera. General Hospital executive producer Frank Valentini announced the star’s death.

“It is with a heavy heart that I announce the passing of my dear friend and colleague Leslie Charleson,” Valentini wrote on X and the General Hospital Instagram account. “Her enduring legacy on General Hospital alone spans nearly 50 years, and just as Monica was the heart of the Quartermaines, Leslie was a beloved matriarch of the entire cast and crew. I will miss our daily conversations, her quick wit and her incredible presence on set. On behalf of everyone at General Hospital, my deepest condolences go out to their loved ones during this difficult time.”

Her exact cause of death has not been released, but Variety noted that Charleson had fallen several times in recent years, limiting her mobility and forcing her to use a walker. She was hospitalized last week after one such fall, Variety reported.

Charleson has played Monica Quartermaine since joining General Hospital in 1977. According to IMDB, she appeared in 2,079 episodes as of 2023. Due to fan objections, she moved to “recurring” status in 2010. She made fewer appearances on the soap, but was still a regular until her final appearance in December 2023.

According to Soap Opera Digest, Charleson was born on February 22, 1945 in Kansas City, Missouri and was hooked on acting at an early age. In 1964, at the age of 19, she appeared in her first soap opera, “A Flame in the Wind,” then appeared as Alice Whipple on “As The World Turns,” followed by a three-year stint on the CBS series “Love “Is a Many Splendored Thing.” from 1967-70.

Charleson was subsequently cast in 1973’s The Day of the Dolphin by Oscar-winning director Mike Nichols. She then tried her hand at Broadway and appeared in One Night Stand with Tony Curtis and William Devane, but when it closed after a short time, she headed to Hollywood.

Over the next few years, Charleson guest-starred on more than 20 popular television shows, including “The Rockford Files,” “The Streets of San Francisco,” “Marcus Welby, MD,” “Mannix,” “Ironside Adam-12,” and “Emergency !” In “Happy Days,” Charleson’s divorcee, Dorothy Kimber, gave actor-director Ron Howard (as Richie Cunningham) his first on-screen kiss, Variety noted.

But soap operas came knocking again and she was cast as Monica Quartermaine – a role she would play for the next 45-plus years. Charleson accompanied her most famous character through marriages, children, breast cancer and a host of other fictional major life events, earning four Daytime Emmy nominations for Best Actress throughout her career.

She later appeared in “Friends” in 2004 and “Dharma & Greg” in 2001.