Founder of the Hells Angels Motorcycle Club Oakland chapter Sonny Barger died of liver cancer on Wednesday. The author, actor, entrepreneur, and convicted felon was 83 years old.

Barger’s death was confirmed in a post made to his Facebook page.

“If you are reading this message, you’ll know that I’m gone. I’ve asked that this note be posted immediately after my passing,” the statement read. “I’ve lived a long and good life filled with adventure. And I’ve had the privilege to be part of an amazing club. Although I’ve had a public persona for decades, I’ve mostly enjoyed special time with my club brothers, my family, and close friends. Please know that I passed peacefully after a brief battle with cancer. But also know that in the end, I was surrounded by what really matters: My wife, Zorana, as well as my loved ones.”

Born Ralph Hubert Barger on October 8th, 1938 in Modesto, CA, Sonny rose to fame after he helped found the Hells Angels Oakland chapter in 1957. Though this was not the first chapter of the infamous outlaw biker organization—the club began in San Bernadino in 1948—it became one of the most widely recognized due to its association with the countercultural movement, for better or worse.

The Oakland Hells Angels chapter developed a close relationship with the Grateful DeadJefferson Airplane, and other 1960s Bay Area psychedelic rock bands. The group provided security at many of the Grateful Dead’s early concerts, which is why when the Rolling Stones approached the band in 1969 about organizing a free show in Golden Gate Park, the Dead recommended the Hells Angels.

Related: Unearthed Altamont Footage Shows The Rolling Stones, CSNY, Santana, More [Watch]

Per journalist Joel Selvin‘s meticulously researched 2016 account Altamont: The Rolling Stones, the Hells Angels, and the Inside Story of Rock’s Darkest Day, a quagmire of poor planning created a power vacuum where it was unclear which chapter of the Hells Angels held authority in the unclaimed region where the Altamont Raceway Park was located. This in addition to myriad factors including a very low stage with no clear barriers, LSD tainted with amphetimines circulating among the crowd, and more led to a fatal confrontation between the Angels and Meredith Hunter, an 18-year-old Black man who was stabbed to death by Club member Alan Passaro in front of the stage during the Stones’ set. Passaro was later found not guilty by self-defense, but the publicity of the concert brought the Hells Angels—specifically Bargers’ Angels—to even further national prominence.

Barger served throughout his life as president of the Hells Angels Oakland chapter, stepping down periodically including in 1973 when he was sentenced to ten years to life for the distribution of heroin and possession of a weapon by a convicted felon. He was paroled in 1977, and would re-enter the penal system a second and final time in 1986 when he received four years for conspiracy to kill members of the Outlaws Motorcycle Club in retaliation for the murder of the Hells Angels Anchorage, AL chapter president John Cleave Webb.

In addition to his reputation as an outlaw biker, Barger was also regarded for his business practice, especially in regards to trademarking the Hells Angels logo. During his tenure as president, he oversaw a widespread licensing effort as the club affixed its logo to everything from t-shirts to wine bottles. Sonny also made much of his income as a consultant for motorcycle movies and books. He landed a small part in Jack Nicholson’s Hells Angels on Wheels and in his later years found a recurring role as Lenny ‘The Pimp’ Janowitz on the FX series Sons of Anarchy.

“The greatest thing that I have learned is probably the simplest thing any of us can learn,” Barger wrote on Facebook in 2015. “I am who I am.”