TORONTO: It’s a long distance from Sid Vicious to Winston Churchill, and a greater leap, still, from Dracula to “Darkest Hour.”

Gary Oldman, character-actor maverick, has taken up perhaps his biggest — and most buttoned-down — challenge. For even a veteran chameleon like Oldman who has a way of hiding in plain sight, the task of tackling such a heroic titan of 20th century history is a leap. If he can disappear behind just glasses (2011′s “Tinker Tailor Soldier Spy”) or merely a mustache (1989′s “The Firm”), what feats of transformation can he accomplish with a pile of prosthetics and a heap of makeup?

The answer is a swaggering, full-throated metamorphosis that has made Oldman the early favorite to win best actor at the Oscars. It’s a part that Oldman grants is a personal mountain peak.

“It’s sort of like my Lear,” Oldman said in an interview over coffee. “And I don’t rule that out. There are some parts still left in the ol’ boy.”

An Academy Awards nomination would be only the second for the 59-year-old Oldman. (He was nominated for “Tinker Tailor.“) His shape-shifting career and preference for privacy has sometimes kept him out of the spotlight, even while his explosive ferocity (“Leon: The Professional,” ″State of Grace,” ″True Romance”) made him a thespian idol.

That Oldman is an actor’s actor is fitting in the case of “Darkest Hour.” Director Joe Wright (“Atonement,” ″Pride & Prejudice”) depicts Churchill as an actor, himself, who’s playing a part. With a Homberg hat and cigar as his costume, he rallies 1940 Britain against pacifism in the face of Adolf Hitler. Churchill, an unpopular figure when he became prime minister, is captured in private self-doubt and public grandeur, as he prods Parliament in famous speeches, like when he warned that with inaction Britain would “sink into the abyss of a new Dark Age made more sinister”

“Our film is about oratory and how words can galvanize the people and move them and rally them. Even simple, direct Anglo-Saxon words,” says Oldman. “I felt it was refreshing because we’ve now got to a world where we communicate with emojis. If Churchill saw an emoji, I think he’d turn in his bloody grave.”

“Darkest Hour” spans just 28 days, when Churchill is thrust into power and Germany is invading France. That Churchill has been so frequently played — among them Richard Burton, Albert Finney, Brian Cox and John Lithgow — gave Oldman pause, since they had, he says, “contaminated” his and our impression of the man.

“I danced around it for a long time. I think I was afraid, to be honest with you,” says Oldman. “But at the end of the day I couldn’t give up saying those words. And what’s the worst that can happen? You stink. They’re not going to come arrest you or shoot you. I thought: Jump off the cliff and see what happens.”

Wright says it took five months to carefully calibrate the makeup and prosthetics: “Too much and you would lose Gary,” he says. Still, Oldman is only just visible underneath.

“The greatest actors I’ve ever worked with have extraordinarily powerful imaginations,” says Wright. “That imagination Gary is able to project with this strength of power of will out of himself.”

The hours of makeup meant Oldman often arrived on set at 3 a.m. His average day, he estimates, was 19 hours long. By the time the rest of the cast and crew arrived, Oldman was already in character. “Joe never saw me as Gary for three months,” says the actor.

“If you’re going to do a part like this, you can’t go in kicking and screaming about the makeup. You’ve got to surrender to it,” Oldman says. “Maybe day 45 you come in, you’re sleep deprived and you’re a bit grumpy. But the fruits of it were such that I could put myself in a frame of mind. Once it was all in, I was in it. I had a ball. My thinking was that if at 65, Churchill could take on Hitler, then I could sit in a makeup chair for three hours.”

“Darkest Hour” isn’t particularly imbued with political relevance for today, though some might watch it pining for Churchill’s leadership. It was purposefully crafted, Oldman says, to place Churchill in his time, not ours. “What we do now, too often, there’s a lot revisionist history,” he says. “We tend to look at the past through the lens of the 21st century.”

Oldman, himself, is no fan of political correctness. In a 2014 Playboy interview he criticized the hypocrisy of the outcry against Mel Gibson’s anti-Sematic tirade. Oldman said everyone is guilty of such slurs and he referred to Hollywood as “run by Jews.” Oldman apologized profusely, including on “Jimmy Kimmel Live.”

Oldman has previously struggled with alcohol addiction (he was charged with drunk driving in 1991) but now doesn’t drink. In August he married his fifth wife, Gisele Schmidt, an art curator.

Asked if he has strong political beliefs, Oldman replies: “I like to know what’s going on. But I’m not an opinion-maker and I’m not running for Congress. I pretty much keep to myself these days. We’ve all got opinions.”

Oldman directed once before in 1997′s searing family drama “Nil By Mouth,” a film that drew heavily from Oldman’s own childhood growing up in working-class East London. (Oldman even wanted to cast his mother.) He plans to be directing again next year from a script not his own, “but the fit is good,” he says.

In the meantime, Churchill still has a hold on him. He finds himself still mumbling some of the film’s lines around the house, like: “I don’t often do that,” which Churchill says after a rare sip of water (as opposed to brandy).

“My reading of Churchill hasn’t stopped. He wrote 50 books and I’m told by scholars that there are 50 by others worth reading. I think I got to about seven,” says Oldman. “I love the footage you can find. I love being a detective. You become like an investigator.”