He helped create one of the most enduring bands in all of music history. The two boys endured a spell in a military school before being swept up in rock music in their teens. He was the first of the great Southern preacher/vocalists. Drugs became so prevalent that the first time they entered their new private plane, they were greeted by the words "Welcome Allman Brothers" spelled out in cocaine on the bar, Gregg wrote in his memoir, "My Cross to Bear".
The seemingly infinite jam sessions that bloomed during the band's live shows earned them not just fans, but followers, and their breakthrough came in 1971 with the live (and largely improvisational) album At Fillmore East.
Cher, to whom Allman was married for four tumultuous years in the 1970s, used pet names and a broken heart emoji to pay tribute. "Through break-ups and line-up changes, we've made 45 years, which is a long time to do anything, brother".
Butch Trucks died in January 2017.
There is no other band who could sell out a run of ten to 15 nights at the Beacon - instantly - from 1989 through 2014.
In the 1990s Gregg Allman moved to California and dabbled in acting, appearing as a drug lord in the 1991 movie, "Rush".
The Allman Brothers reunited in 1989 and would tour on and off over the next 25 years.
What had once been a familial group split up over what was seen as Allman's betrayal.
Gregg was the band's lead singer, keyboardist and a key songwriter as it put out a string of hits.
The statement says Allman had struggled with many health issues over the past several years. On Saturday, May 27, 2017, a publicist said the musician, the singer for The Allman Brother. "Playing music lifted him up and kept him going during the toughest of times", the statement said.
Allman died due to liver cancer complications at his home in Savannah, Georgia, and he was "surrounded by his family and friends", Michael Lehman, Allman's longtime manager and close friend, told CNN. His love for his family and bandmates was passionate as was the love he had for his extraordinary fans. Then we lost him and Berry Oakley, but we carried on.
"The family will release a statement soon, but for now ask for privacy during this very hard time", the statement on his website advised.