Jon S.Baird wanted to make sure the 'Stan & Ollie' script was "perfect" before shooting the movie.
The director's latest comedy drama - which stars Steve Coogan as Stan and John C. Reilly as Ollie - tells the story of the legendary comedy duo, Laurel and Hardy, after their fame had peaked and they set out on a tour to reconnect with their adoring fans.
However, the filmmaker revealed that the movie - which has been nominated for a trio of BAFTA awards - was initially going to be a TV project for the BBC.
Jon explained that when he cast Reilly, the script really started to "build" and take shape.
Speaking to Deadline, Baird shared: "I had the first meeting at the start of 2014. I was working with Danny Boyle on 'Babylon' for Channel 4 and ['Stan & Ollie's screenwriter] Jeff Pope approached me. It started out as a TV project for BBC Comedy, but it sort of outgrew that. Christine Langan, who was the head of BBC Films at the time, said, 'We'll take it.' It slowly started to build.
"The reason it took so long was that we wanted to get the script absolutely perfect. The final script was a million miles from where the original script started. The person who really kick-started the script into what it became was John C. Reilly. Not by writing on it, or anything, but by coming to the table and saying, 'You know what? This needs to be more about these two guys.' John was a force in crystallising that."
Reilly was working alongside Will Ferrell at the time on the film 'Holmes and Watson', so the movie had to wait - which is when the director got to work with Martin Scorsese on the HBO series 'Vinyl'.
He added: "If I were him I'd have done the exact same. 'Holmes & Watson' was one because he hadn't worked with Will Ferrell in a long time and he really wanted to work with him.
"During that time I had to say, 'Great, I'm not going to be taking another film,' because I knew if I did, it would rule me out of this. I wanted to stay attached, and so I took TV projects.
"That's when I got the chance to work with Martin Scorsese on 'Vinyl', and that's been massive for me. I didn't think I'd ever meet someone like him."
Tagged in Steve Coogan John C. Reilly