Oasis was one of the biggest bands of the 1990s and 2000s until the band’s ugly breakup in 2009 after years of public feuding by sibling bandmates Liam and Noel Gallagher caused the whole thing to self-destruct.

A new documentary, “Liam Gallagher: As It Was”, chronicles Gallagher’s life and career in the years after the implosion of Oasis.

“It was pretty vicious and pretty nasty,” Gallagher says of the split with his brother.

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“The geezer split me band up,” he adds. “No wonder we hate each other.”

There are some brutally honest moments in the doc, including one of Gallagher riding in a limo while half-joking, “No one knows who I am anymore.”

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While Gallagher often comes across as cocky and cantankerous in interviews, “As It Was” shows a different side of the 46-year-old rocker, who appears pensive and nervous as he prepares to unveil his new solo music to the world. “This is my last chance to do the thing I love,” he says.

“Controversial Oasis frontman Liam Gallagher gives unparalleled access into his life after his public blow up with brother and bandmate, Noel,” reads the film’s official synopsis. “See how his fall from superstardom turned into the visionary launch of a solo career.”

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“Liam Gallagher: As It Was” hits theatres on Sept. 13, and will be available for digital download on Sept. 17 and VOD on Oct. 8.