Charles Manson, the hippie cult leader who became the hypnotic-eyed face of evil across America after orchestrating the gruesome murders of pregnant actress Sharon Tate and six others in Los Angeles in 1969, has died after nearly a half-century in prison.

Manson, 83, whose name to this day is synonymous with unspeakable violence and madness, died of natural causes at Kern County hospital, according to a California Department of Corrections statement.

A petty criminal who had been in and out of jail since childhood, the charismatic, guru-like Manson surrounded himself in the 1960s with runaways and other lost souls and then sent his disciples to butcher some of LA’s rich and famous in what prosecutors said was a bid to trigger a race war – an idea he got from a twisted reading of the Beatles song Helter Skelter.

The killings horrified the world and, together with the deadly violence that erupted later in 1969 during a Rolling Stones concert at California’s Altamont Speedway, exposed the dangerous, drugged-out underside of the counterculture movement and seemed to mark the death of the era of peace and love.

Despite the overwhelming evidence against him, Manson maintained during his tumultuous trial in 1970 that he was innocent and that society itself was guilty.

“These children that come at you with knives, they are your children. You taught them; I didn’t teach them. I just tried to help them stand up,” he said in a courtroom soliloquy.

The Manson Family, as his followers were called, slaughtered five of its victims on August 9 1969 at Tate’s home: the actress, who was pregnant, coffee heiress Abigail Folger, celebrity hairdresser Jay Sebring, Polish movie director Voityck Frykowski and Steven Parent, a friend of the estate’s caretaker.

Tate’s husband, Rosemary’s Baby director Roman Polanski, was out of the country at the time.

Charles MansonCharles Manson sent a group of disaffected young followers to commit murder in 1969 (California Department of Corrections and Rehabilitation via AP)

The next night, a wealthy grocer and his wife, Leno and Rosemary LaBianca, were stabbed to death in their home across town.

The killers scrawled such phrases as “Pigs” in blood at the crime scenes.

Three months later, a Manson follower was jailed on an unrelated charge and told a cellmate about the bloodbath, leading to the cult leader’s arrest.

In the annals of American crime, Manson became the embodiment of evil, a short, shaggy-haired, bearded figure with a demonic stare and an “X” – later turned into a swastika – carved into his forehead.

After a trial that lasted nearly a year, Manson and three followers – Susan Atkins, Patricia Krenwinkel and Leslie Van Houten – were found guilty of murder and sentenced to death. Another defendant, Charles “Tex” Watson, was convicted later.

All were spared execution and given life sentences after the California Supreme Court struck down the death penalty in 1972.

Atkins died behind bars in 2009. Krenwinkel, Van Houten and Watson remain in prison.

Another Manson devotee, Lynette “Squeaky” Fromme, tried to assassinate President Gerald Ford in 1975, but her gun jammed. She served 34 years in prison.