The two-part Eagles documentary, History of the Eagles - The Story of an American Band, premieres this Friday and Saturday on Showtime.

Directed by Academy Award-winning documentary filmmaker Alex Gibney, the film takes you behind the band's 42 years, warts and all. Glenn Frey says he had to give assurances to Gibney that they'd be "telling the truth." And Don Henley adds that the film will show some of the private moments of their career that they have "never allowed before."

In addition to the current lineup, the film also contains interviews with many associates, as well as former members Bernie Leadon, Randy Meisner and Don Felder. Henley says, "We don't really care what anybody says. That's why all the ex-band members are in it. Everybody wants to get their licks in. Let them say what they wanted to say."

Part one of History of the Eagles - The Story of an American Band airs at 8 p.m. ET/PT Friday on Showtime, with part two at the same time on Saturday.