The Godfather is pretty much universally held to be one of the finest movies in cinema history, but its lead star Al Pacino has made a surprising revelation: he thought it was “the worst film ever made” while he was filming it, and frequently got drunk as a result.

Many surviving members of the cast of the iconic 1972 film attended a 45th anniversary celebration of its release in a New York theater on Saturday (April 29th) as part of the Tribeca Film Festival. In addition to Pacino, fellow stars Robert De Niro, Robert Duvall, Diane Keaton, James Caan and Talia Shire, as well as director Francis Ford Coppola, were in attendance.

Al PacinoAl Pacino initially thought 'The Godfather' would fail

The day-long event featured showcase screenings of the original movie and its equally-acclaimed 1974 sequel The Godfather II, and in-depth Q&A sessions with the cast that yielded fascinating insights on what it was like to work on the film, which many argue is the greatest ever.

However, the most headline-grabbing moment came when Pacino discussed the opening wedding scene.

“We got back, and we started drinking and we were just talking about 'where do we go from here? We're done. It's the worst film ever made’,” the 77 year old film legend said, according to a report by the Daily Mail.

More: De Niro, Pacino and Scorsese to team up once again for mob film ‘I Heard You Paint Houses’

Even though it’s one of his most famous roles, director Coppola said that the decision to cast Pacino as Michael Corleone was not without its troubles. “I just saw his face,” he remembered. “Once you see someone in the role, it’s very hard to get that out of your head.”

Paramount, however, didn’t fully back Coppola in his confidence in this regard. Pacino recalled “countless” screen tests. “It seemed like I was always testing. I was still testing after I got the part.”

“I was attracted to it because I thought it was a foreign author, and an intellectual book about power,” Coppola said about when he first encountered the original 1969 novel by Mario Puzo.

However, his decision to sign on to direct it was not without some hesitations. “I was disappointed in the book when I first read it because it’s very long,” he said. “Much of the book — about a third — is about Lucy Mancini’s anatomy.”

More: How did a film starring Al Pacino and Anthony Hopkins manage less than £100 at the UK box office?