No other casting process has been as exhausting for fans than the one that we endured when it came to casting Stephen Strange. Back in June of 2014, a shortlist of actors made its way online, courtesy of Deadline, that included Tom Hardy and Benedict Cumberbatch. Two names. Not too bad, right? Yeah, that shortlist was then followed by numerous reports and rumors that seemed to include every working actor in Hollywood. At one point, it looked as though Joaquin Phoenix would sign on for the titular role, but talks ended up falling apart, leaving the role up for grabs still. During this time, various other names made their way into the mix – Jared Leto, Oscar Issac, Jake Gyllenhaal, and Ethan Hawke to name a few – but in the end, it came back to Cumberbatch, who at the time seemed unlikely with such a busy schedule. For Marvel, however, no one else could top him and they ultimately found a way to work around his schedule in order to bring him on board.

Entertainment Weekly had a chance to talk to Marvel Studios head Kevin Feige about the casting process for Doctor Strange, and how they decided to cast Cumberbatch in the highly coveted role. According to Feige, Cumberbatch was essentially always the one to beat for the role – but his busy schedule made it difficult to get him to sign on.

“He was someone that we were very interested in for a very long time,” says Feige, talking on the London set of Doctor Strange. “[But] he kept getting more and more popular! [Laughs] Which is not [essential] for us. Chris Pratt was not popular when we cast him in Guardians. That’s not a prerequisite needed for us casting [someone]. But he kept getting more popular, and more popular, and he kept getting busier, and busier, and it looked like the timing wasn’t going to work.” So we looked at some other actors for a while and ultimately decided, ‘We have to try and make it work with Benedict and with his schedule.’ Which is why we shifted the production schedule around. He finished Hamlet here in London, and I think had a day off, and then went to Kathmandu, Nepal, to shoot the first day of Doctor Strange.”

As for Cumberbatch, playing Stephen Strange wasn’t something he had to do – it wasn’t something on a bucket list that he needed to do. In fact, it was actually his time teaching Tibetan monks when he was younger that led to him taking on the role.

So how come Cumberbatch is doing just that in a soundstage around 25 miles west of London on an early December afternoon? The answer lies in Cumberbatch’s teenage years — specifically when the 19-year-old Brit spent time teaching English to Tibetan monks in the state of West Bengal in eastern India. “It was a very unfair exchange,” says the Sherlock star. “Basically, they taught me reams, fathoms, more than I could possibly begin [to teach them]. I became interested the meeting point between Western logic and Eastern mysticism.”

After he took the time to research who Doctor Strange was, and the character’s origin story, Cumberbatch found himself drawn to the uniqueness of the story and the character.

“I knew it was on their slate, I knew it was coming up, so I got invested in it and I was interested,” he says. “What happens here in this origin story is, Strange realizes the power he has within his body is not about his body. It’s something that’s beyond the causal-temporal-linear-reality that he knows so well as a [surgeon]. We come from this very causal world into this mystical, magical world of other realms and sorcery.”

Doctor Strange, which is currently filming in London, is set to hit movie theaters on November 4th, 2016.

Sources: Entertainment Weekly 1 and 2.