Australian author Colleen McCullough has died after a long illness, aged 77.
The writer was best known for her novel The Thorn Birds, a romantic Australian saga, which has sold 30 million copies worldwide since it was published in 1977.
It was also made into a television series.
HarperCollins Australia publishing director Shona Martyn said McCullough died on Thursday in a hospital on Norfolk Island, the remote isle where she had lived for 40 years.
McCullough had previously lost her eyesight but continued producing books by using dictation. She was also restricted to a wheelchair.
Before becoming an author, McCullough studied neuroscience and spent 10 years as a researcher at Yale Medical School in the United States.
She established the neurophysiology department at Sydney's Royal North Shore Hospital.
During her career she wrote 25 novels and her final work Bittersweet, about four sisters in 1920s and 1930s Australia, was completed in 2013.
McCullough had even been dictating a sequel, set in World War Two, but had only completed a third of it when she died.
She is survived by her husband, Ric Robinson, who she married in 1983.