Fans of The Eagles have spent decades wondering what went wrong with what was, for a time, one of the most popular rock bands in the world.

The group entered a media cone of silence for a while, but its members recently allowed the camera to be turned on themselves in Alison Ellwood's new documentary, which promises to tell the story of The Eagles’ formation, chart-topping hits such as “Hotel California,” and what’s happened since they reunited in 1994.

“History of The Eagles Part One” made its debut Saturday night at the Sundance Film Festival in Park City, Utah. And it will be telecast Feb. 15 on the cable-television network Showtime, which will present “History of The Eagles Part Two” the following night.

“It was time to get it down if we were going to do it,” drummer and singer Don Henley said during a press conference before the documentary's premiere. “It could come to a screeching halt tomorrow. We thought it was time.”

The Eagles -- currently consisting of Henley, Glenn Frey, Timothy B. Schmit, and Joe Walsh -- dropped the studio album “Long Road Out of Eden” in 2007, but Frey hinted there is a chance more new music could be released in the future, according to the Los Angeles Times.

“Most of the things that have been written about this band have focused on conflict -- the journalism of conflict,” the Associated Press quoted Henley as saying. “It sells papers and magazines, but one thing that Glenn said that people will see in this documentary is that we had a lot of fun. Some of it's not on film, and that's good.”

The Eagles documentary will feature talking-head interviews with the band's members and those close to them, interspersed among their own personal home videos, as well as footage assembled for a never-released 1977 documentary.

Henley said he had not been impressed by recent music documentaries, so he commissioned director Ellwood (“Magic Trip”) and producer Alex Gibney (“Taxi to the Dark Side”) to explore the history of The Eagles.

“You can see the character of the band, how open they were and more casual, off-the-cuff,” Gibney told Billboard. “You can see how different they are and how they complement each other.”

“We were very private. We didn’t allow access,” Henley said. “We tried to keep it in-house. But we had the foresight to film some backstage stuff. And that’s in the film.”

Check out The Eagles performing "Hotel California" below.