Since his magisterial Cannes lead actor-winning turn as director Mike Leigh’s “Mr. Turner,” English thesp Timothy Spall is more in demand than ever. Now he essays two other real-life people: the Rev. Ian Paisley, Northern Ireland’s firebrand Protestant leader, in director Nick Hamm’s TIFF title “The Journey,” and Holocaust-denying historian David Irving in “Denial,” directed by Mick Jackson.

What attracted you to these two projects?
Both were immense, rather daunting challenges. “The Journey” is a remarkable piece about the power of reconciliation. I grew up with that going on over there in Northern Ireland and the consequences of those troubles affected the mainland as well. It was daunting because I knew it was a hot potato, and interesting because it had all these elements about the factions, the troubles, all these polar points of view. “Denial” was another controversial and, for a lot of people, deeply upsetting subject. The people themselves are so fascinating. It’s interesting what makes such controversial characters tick.

What special challenges are there in playing well-known figures?
It’s very important to me that it isn’t an impersonation. It’s a massive responsibility to try to capture someone without impersonating. You know what they look like, how they spoke, but can’t look exactly like them, can’t become them. You study them a lot, look at them, try to become them in how they speak, how they stand, how they are. You find something about them that is very personal, you try to catch a bit of their soul in you.

Both Paisley and Irving are divisive characters. How do you make them understandable or even sympathetic?
However you feel about them, whatever is the perceived wisdom, your job is not to judge them from the outside, but to take their point of view, wherever it comes from. Then you are doing yourself and the character the most honest favor. Both Paisley and Irving had an incredible, unflinching ability to go through what they believed despite massive amounts of resistance.

During “Mr. Turner,” you learned to paint; what is your takeaway from these roles?
I haven’t assimilated them yet. It’s still too close, but we will see. I am suffering a little from that thing you get as you grow older, that you see both sides. As you get opportunities to play these interesting, controversial, complex characters, it increases your understanding of the frailty of the human condition. You start to understand it more, but it doesn’t make you any less appalled. You never stop learning about the difficulties and the challenges of the human condition.

What else is in the pipeline?
After Venice and Toronto, I’m off to New Zealand to do a supernatural film called “The Changeover,” based on a famous young adult book. I play a character who at first seems like a rather benign old gentleman, but without giving too much away, he obviously isn’t. It’s about a young girl’s relationship with him, her changing from girl to woman and realizing her supernatural powers. I’m looking forward to that.