Cult leader Charles Manson, whose followers killed actress Sharon Tate and six others in a string of ritualistic murders in California in 1969, has died.
The 83-year-old died of natural causes on Sunday night, according to the California Department of Corrections, after months of failing health.
Manson, who had a Swastika etched between his eyebrows, spent the past four decades in prison after being given nine life-sentences.
He never killed anyone himself but directed his followers to do so.
The killings occurred on successive August nights, terrorising the city of Los Angeles.
Tate, the wife of famed director Roman Polanski, was nearly nine months pregnant when she was found stabbed repeatedly in her Hollywood mansion, along with several of her friends. Other victims included coffee heiress Abigail Folger and celebrity hair stylist Jay Sebring. They had been tied up and massacred by Manson's followers, stabbed collectively 102 times.
The horrifying episode was followed by a double-murder the next night of a supermarket executive and his wife
The two-day spree became known as the Tate/LaBianca killings.
Other celebrities including Frank Sinatra, Elizabeth Taylor and Steve McQueen were reportedly targets for "The Family", as Manson and his followers became known.
Investigators learned Manson sent a group of disaffected young followers to commit murder as part of a quasi-religious belief that it would launch a race war from which The Family could emerge as rulers.
The killings and subsequent proceedings mesmerised Los Angeles and made global headlines.
After a seven-month trial, Manson and four followers were convicted and received the death penalty in 1971; yet a year later the penalty was temporarily abolished and the sentences changed to life imprisonment. He showed no remorse for his crimes.
Ms Tate's sister, Sharon, said a prayer for Manson's "soul" after being informed of his death by the prison. She told CBS that she had "forgiven the family but refuses to forget what they did".
Newspapers restarted the presses to update their front pages, with The New York Post's reading: "Evil dead: Make room, Satan, Charles Manson is finally going to hell."
Who was Charles Manson?
Manson was born Charles Milles Maddox on November 12, 1934, in Ohio to a 16-year-old, drug-addict prostitute mother.
Shunned by mum Kathleen - who briefly married a man called William Manson - the nascent sociopath spent much of his early life in prison.
It is thought he never met his father, a colonel.
In 1955, he moved to California with a 17-year-old lover in tow, settling into a routine of theft and incarceration in San Francisco.
Manson was jailed for 10 years for forgery and released in 1967 - the year before he orchestrated a killing frenzy that would scorch his name into history.
Caught in a swirl of hallucinogenic drugs, belief in the apocalypse, and an impending race war, the deluded narcissist recruited burned-out, malleable, middle-class followers.
The Family, as they became known, lived on isolated ranches - one in Death Valley - and grew drunk on Manson's claim to be a prophet sent to warn of the coming "Helter Skelter" ethnic conflict.
The charismatic visionary would pump his slavish followers with LSD and re-enact the crucifixion while they were tripping, former cult members said. Whatever he believed, they would too.
At its height, The Family reportedly had around 100 members and was a mix of both men and women.
Manson was married twice and had at least two children, although the real figure could be higher.