Gregg Allman, whose hard-jamming, bluesy sextet the Allman Brothers Band was the pioneering unit in the Southern rock explosion of the ‘70s, died Saturday due to complications from liver cancer, his longtime manager, Michael Lehman, confirmed to Variety. He was 69.

As recently as April 24, reports surfaced claiming Allman was in hospice, although Lehman denied those reports, which Allman then substantiated in a Facebook post. However, he had suffered a number of ailments in recent years — including an irregular heartbeat, a respiratory infection, a hernia and a liver transplant — and cancelled many scheduled tour dates in recent months for health reasons. Lehman said that Allman’s liver cancer recurred around five years ago, but the singer chose to keep the news private.

Allman completed a solo album, “Southern Blood,” that is set for release late this year. Lehman said they received some final mixes for the album on Friday, and Allman listened to them the night before his death. He added that Allman passed away with his family nearby, and was “at peace.”

For his work with the Allman Brothers, the legendary band he cofounded with his late brother Duane, and as a solo artist, Allman is one of the leading lights of Southern Rock. While the group’s greatest work was done before and shortly after Duane’s death in 1971, they stayed together, off and on, over 45 years and remain a singular influence on Southern rock and jam-band musicians. They were a top-drawing touring outfit until October 2014, when the group finally closed the book on their career with a series of dates at their longtime favorite venue, New York’s Beacon Theatre.

Allman’s solo career always played second to that of the band, but he enjoyed solo success with 1973’s “Laid Back” and 1987’s “I’m No Angel,” both of which were certified gold. In 2011 he released an unexpectedly strong album entitled “Low Country Blues” that was produced by T Bone Burnett (Alison Krauss/Robert Plant, Los Lobos, Elvis Costello, “O Brother Where Art Thou?”), who, along with instrumentalists like pianist Dr. John and guitarist Doyle Bramhall II, brought Allman back to his gutsy roots with stellar results.

With his older sibling, guitarist Duane Allman, the singer-keyboardist-guitarist-songwriter led one of the most popular concert attractions of the rock ballroom era; the group’s 1971 set “At Fillmore East,” recorded at Bill Graham’s New York hall, was a commercial breakthrough that showed off the band’s prodigious songcraft and instrumental strengths.

After Duane Allman’s death in a motorcycle accident weeks after the live album’s release, his younger brother led the band through four more stormy decades of playing and recording. The Allman Brothers Band’s latter-day history proved tumultuous, with other fatalities, disbandings, regroupings and very public battles with drugs and alcohol on the part of its surviving namesake.

Though Gregg Allman’s highly publicized addictions, his tabloid-ready marriage to pop vocalist Cher, and his equally public disputes with co-founding guitarist Dickey Betts came under harsh and sometimes mocking scrutiny over the years, Allman prevailed as the linchpin of an act that maintained popularity over four decades and opened the commercial door for such other Southern acts as Lynyrd Skynyrd and the Marshall Tucker Band.

As a member of the Allman Brothers Band, Allman was inducted into the Rock and Roll Hall of Fame in 1995 and was honored with a Grammy Lifetime Achievement Award in 2012.

He was born Gregory LeNoir Allman on Dec. 8, 1947, in Nashville; brother Duane was born 13 months earlier in the same hospital. In 1949, his father was shot to death by a man he offered a ride to in a bar. As their mother was studying accounting to support the family, the brothers were sent to a Tennessee military school at an early age.

The Allmans became attracted to music after seeing a 1960 concert by R&B singer Jackie Wilson in Daytona Beach, FL, where the family had moved the year before. Using money from a paper route (augmented by his mother), Gregg bought a guitar, and taught Duane his first chords. Both played guitar in the bands they founded after returning to the military academy in their teens.

Their pro bands the Escorts and the Allman Joys, which favored R&B, blues and rock covers, found work on the Florida club circuit in the mid-‘60s; Gregg began playing keyboards in the latter unit. The Allman Joys were playing without success in St. Louis when Bill McEuen, manager of the Nitty Gritty Dirt Band, met them and offered to set them up in Los Angeles.

Renamed Hour Glass, the L.A.-based group cut two unsuccessful pop-oriented albums for Liberty Records in 1967-68. Duane chafed at the direction being forced on the combo and fled for Alabama, where he became a prominent session guitarist at FAME Studios in Muscle Shoals, AL. Gregg remained in L.A. to fulfill obligations to Liberty, but was summoned to Jacksonville, FL, in 1969 by his brother, who envisioned a new blues-based band with two guitarist and two drummers, featuring members of another local combo, the 31st of February.

Calling themselves the Allman Brothers Band, the new unit – the Allmans, guitarist Betts, bassist Berry Oakley and drummers Butch Trucks and Jai Johanny “Jaimoe” Johanson – was signed by Otis Redding’s former manager Phil Walden for management and as an act on his Macon, GA-based label Capricorn Records. The group moved to Macon, which became its base for the duration.

Neither of the ABB’s first two albums was an enormous success: Its self-titled bow peaked at No. 188 in 1969, while sophomore set “Idlewild South” topped out at No. 38 in 1970. But they established Gregg Allman as a vocal, instrumental and songwriting power: His compositions included such future staples of the band’s live set as “Not My Cross to Bear,” “Dreams,” “Whipping Post” and “Midnight Rider.”

Though problems with hard drug abuse were already surfacing in the band, the Allmans became a huge concert attraction in the South; the enthusiastic sponsorship of promoter Graham led to high-profile gigs at New York’s Filllmore East (where the band attained a rabid following) and San Francisco’s Fillmore.

The Allmans made their commercial mark with “At Fillmore East”: The expansive, Tom Dowd-produced two-record set, recorded during two nights at the venue, shot to No.13 ultimately sold more than 1 million copies and became one of the defining concert recordings of its day. However, Duane Allman’s tragic death at 24 on a Macon street on Oct. 29, 1971, cast a shadow over its success.

The band completed a follow-up two-LP set, “Eat a Peach,” as a quintet, with live numbers featuring Duane filling out the contents. The 1972 package rose to No. 4 nationally and went platinum, but disaster again struck: In a mishap eerily similar to Duane Allman’s fatal crash, hard-drinking bassist Oakley died after driving his bike into the side of a truck that November.

Shaken by the deaths of his brother and Oakley and increasingly incapacitated by heroin, cocaine and alcohol, Gregg Allman ceded much of the band’s songwriting and front man duties to Betts; as he noted in “My Cross to Bear,” his 2012 memoir, “Up until then, we’d never really had a front man; Dickey took it upon himself to create that role.”

The ABB released its only No. 1 album, “Brothers and Sisters,” in 1973; the record was powered to the top by the Betts-penned No. 2 single “Ramblin’ Man,” the group’s only top-10 45.

Allman retreated from the group to cut his solo debut “Laid Back” in 1973; rising to No. 13, it would be his most popular work away from the band for nearly 40 years, and it spawned his only top-20 solo single, a down-tempo remake of “Midnight Rider.”

On the heels of the lugubrious but popular “Win, Lose or Draw” (No. 5, 1975), the group set out on its biggest, and costliest, tour to date. The ABB flew to its dates on a lavishly appointed private jet previously used by the Rolling Stones and Led Zeppelin; in his book, Allman recalls, “The first time we walked onto the plane, ‘Welcome Allman Brothers’ was spelled out in cocaine on the bar.”

The ABB returned from the 41-date tour with a mere $100,000 in hand, owing to over-the-top spending. This financial catastrophe was compounded by the indictment of the group’s security man (and Allman’s drug bag man) Scooter Herring on cocaine distribution charges; Allman testified against Herring before a grand jury and at his trial, which netted a 75-year prison sentence.

Addicted to heroin and embroiled in inter-band conflict with Betts, Allman began spending more time in Los Angeles with Cher, whom he had wed in June 1975. The incongruous couple was followed avidly by gossip columnists. In the wake of an unsuccessful 1977 solo album, “Playin’ Up a Storm” (No. 42), Allman and Cher released their only duo album, “Two the Hard Way”; embarrassingly credited to “Allman and Woman,” the set failed to chart, and its accompanying tour witnessed scuffles between hostile camps of fans in the audiences. Allman and Cher divorced in 1978.

Membership in the ABB rotated repeatedly for the remainder of the group’s career, which saw ever-diminishing contributions from writer Allman. He authored just one song for the group’s final Capricorn album, “Enlightened Rogues” (No. 27, 1979); the financially unstable imprint crashed within a year of its release. Allman was also a minor contributor to a pair of slick, poorly received albums for Arista Records in 1980-81.

During the band’s protracted hiatus of the ‘80s, Allman issued a pair of solo sets; the more popular of the two, 1987’s “I’m No Angel” (No. 30, 1987), spawned the titular radio hit.

Encouraged by airplay on the burgeoning “classic rock” radio format, the ABB reconvened for a 1989 tour. In 1990, the group recorded “Seven Turns” (No. 53) with “Fillmore East” producer Tom Dowd; the group also began multi-night residencies at New York’s Beacon Theatre, which became an annual tradition. They issued four commercially unrewarding albums – two studio sets and two concert releases – between 1991 and 1995.

Following a drunken appearance at the Rock and Roll Hall of Fame induction ceremony in New York in January 1995, onetime junkie Allman, after 11 stints in rehab, finally stopped drinking on his own, under the 24-hour watch of two nurses.

Following the exit of longtime guitarist Warren Haynes and bassist Allen Woody and the recruitment of Butch Trucks’ young nephew Derek Trucks on guitar, the ABB cut the live “Peakin’ at the Beacon” in 2000. Tension within the band had reached the breaking point, and, following a severely worded fax to Betts from the other members and subsequent legal arbitration, the Allman Brothers Band’s other founding guitarist made his exit.

The front line of Allman, Haynes and Derek Trucks and the group’s founding drummers were heard on the Allman Brothers Band’s studio collection “Hittin’ the Note” (No. 37, 2003) and the live “One Way Out” (No. 190, 2004). After 45 years in business, the band was formally dissolved after an October 2014 show at the Beacon.

Allman’s old habits caught up with him in the ‘00s. Diagnosed with hepatitis C – a disease common to intravenous drug users – in 2007, he learned that he was suffering from liver cancer in 2008. He underwent successful liver transplant surgery at the Mayo Clinic in 2010.

Before his surgery, Allman entered the studio to record his first solo album in 13 years. “Low Country Blues,” a striking and powerful recital of old blues songs, augmented by one Allman-Haynes original and produced by T Bone Burnett (Alison Krauss/Robert Plant, Los Lobos, Elvis Costello, “O Brother Where Art Thou?”), garnered the best reviews of his career, collected a Grammy Award nomination and became his highest-charting solo release, reaching No. 5 in early 2011.

However, health problems and catastrophe continued to dog him. He cut short a 2011 European tour because of respiratory issues, which ultimately mandated lung surgery. He faced a drug relapse spurred by painkillers, and did a stint in rehab. In 2014, a film based on his 2012 memoir, “Midnight Rider,” ceased production after a camera assistant on director Randall Miller’s feature was killed by a freight train on the first day of shooting.

Allman’s last concert took place on October 29, 2016 in Atlanta, a headlining set at his own Laid Back Festival.

Married and divorced six times, Allman is survived by three sons and two daughters, all by different mothers. Four of the children are professional musicians.