Jeanne Cooper DEAD -- 'The Young And The Restless' Star Dies At 84

Jeanne Cooper, a huge soap opera star who played Katherine Chancellor on "The Young and the Restless" for decades, has died. She was 84.

"L.A. Law" star Corbin Bernsen -- Cooper's real-life son -- tweeted this morning that she had passed away. She had fallen ill with an infection earlier this year after helping promote "Y&R's" 40th anniversary.

Cooper joined the show soon after its 1973 debut and had been nominated for 10 Daytime Emmys going back to '89 ... she finally won for lead actress in 2008.

Cooper was married to TV producer Harry Bernsen, Jr. for 23 years before divorcing ... all three of their children -- Corbin, Collin and Caren -- are actors.

Her character Katherine was groundbreaking in daytime ... she went through bouts of alcoholism, lost four husbands and a child ... and even had lesbian flings. But her most famous thread was a bitter feud with Jill Foster Abbott ... including this epic catfight: