Riley Keough has unveiled a heartbreaking letter written by her late mother, Lisa Marie Presley, in which she begged her father Elvis not to die. Elvis Presley, who died in 1977 aged just 42, suffered with health problems in his later life – his daughter Lisa Marie was only nine years old at the time of his death.

Lisa Marie Presley's raw memoir "From Here to the Great Unknown" is out now. Ahead of Oprah's Riley Keough interview, these are the biggest reveals.

Riley Keough recalled how her mother Lisa Marie Presley, only nine years old at the time, sensed something was wrong on the day Elvis Presley died in August 1977. “She woke up and felt something was not right,” the actress told Oprah. Elvis died later that day at the age of 42 at his Graceland home.