Many moviegoers may not know just how to pronounce his name, but they easily recognize Welsh actor Ioan Gruffudd from his roles in “Titanic,” “King Arthur,” “Fantastic Four,” and the series of “Horatio Hornblower” telefilms broadcast on the A&E Network. Now they have the opportunity to see him play British politician William Wilberforce (1759-1833) in Michael Apted’s “Amazing Grace,” which details the decade-and-a-half crusade of the statesman (and evangelical Christian) to persuade Parliament to pass a law abolishing the slave trade in England.

“It was such a wonderful, satisfying experience every day,” Gruffudd said in a recent Dallas interview, “to come to work, because of the nature of the subject and working with Michael Apted, who’s such an experienced and talented director, and because of this great, brilliant script. It was such a pleasure to speak those words every day.”

But it was a screenplay that had passed through various forms before being brought to the screen. It “existed for several years as a biopic,” Gruffudd explained. “And movies which are biopics tend not to be that exciting or that story-driven. I think that’s why this one works, because it’s such a definite story—trying to get over this obstacle which took fifteen years, condensed into an hour and forty minutes. It’s so subtle. We’re not knocking everybody over the head with the fact that he was an evangelical Christian and had a religious conversion. You’re just seeing it very subtly through the story of trying to pass this one bill in Parliament.”

But Gruffudd readily admitted that before reading the screenplay, he wasn’t aware of Wilberforce. “No, not at all,” he said. “You have to forgive my ignorance. When I read the script and then subsequently researched as much as I could to get under his skin, it was a very humbling experience—somebody who dedicated his entire life not just to this cause, but several causes, the reformation of society, education, the disabled, the Society for the Prevention of Cruelty to Animals. He just gave every minute of his life to try to help others. He was such a generous, generous soul—and coming from such a small man, physically small. He was about 5’1’’, so they describe him as this little shrimp of a character that would grow into a whale as he continued to orate. It was a great experience to think that somebody like Michael Apted thought I was the right choice to play this great man. I’m so lucky. I’ve played Hornblower and all these heroic figures, and then they sort of reflect well on me. That’s a lot to live up to. It’s kind of eerie to walk in the footsteps of these great men.”

Gruffudd also appreciated the opportunity to share scenes with a cast of celebrated co-stars. “It was terrifying,” he said. Of Ciaran Hinds and Toby Jones, who play Wilberforce’s chief parliamentary opponents, he remarked, “I have such admiration for them both as actors. They’re so good, they make it look so easy and effortless.” And of Michael Gambon, who plays Lord Charles Fox, Wilberforce’s unlikely ally, he added, “To be in the same room with Gambon, there’s a smile on your face the whole time. You just never know what’s going to happen. And Albert Finney! It’s just overwhelming to have these images up on the screen of me with him in the same scene. To have that for posterity is really something special.”

As to his own name, Gruffudd admitted that people in the business have tried to get him to change it, or at least the spelling. “They have for many years, from the beginning of my career,” he said with just a hint of annoyance. “And either foolishly or not, I’ve stuck with it. I think it’s a matter of educating people, really.” And with his work in pictures like “Amazing Grace” and the forthcoming sequel to “Fantastic Four,” he’s educating them very well.