Veteran U.S. soap star Jeanne Cooper has died at the age of 84. The actress passed away on Wednesday morning (08May13) after a long battle with a mystery illness. Her actor son, Corbin Bernsen, took to Twitter.com to break the sad news to fans, writing, "Mom passed this morning. She was in peace and without fear. U all have been incredible in your love. In her name share it 2 day with others (sic)." Cooper began her career in the 1950s and scored her big break in 1953 western The Redhead from Wyoming. She went on to land roles in movies like The Man from the Alamo, House of Women, The Glory Guys and Kansas City Bomber. She made the transition to TV with parts in series such as Crossroads, Tales of Wells Fargo and Perry Mason, and earned her first Emmy Award nomination for her performance in medical drama Ben Casey in 1962. However, her biggest break came in 1973 when she was cast as Katherine Chancellor on the long-running U.S. soap opera The Young and The Restless, a role she played right up until her death. The Chancellor character earned her multiple Daytime Emmy nominations and she finally won the Outstanding Lead Actress in a Drama Series title in 2008. She was also awarded a Lifetime Achievement Emmy in 2004, 11 years after unveiling her own star on the Hollywood Walk of Fame. Cooper suffered from ill health in her final years and had to take medical leave from The Young and The Restless in October, 2011. She returned two months later, but was struck down with another health issue in early 2013 and had been in and out of hospital in the weeks leading up to her death.