‘Shōgun’ Star Cosmo Jarvis Almost Made His John Blackthorne Voice Even Weirder Until The Showrunners Stepped In

In case you’re wondering, no, that’s not what Shōgun star Cosmo Jarvis — the English actor behind the bold Protestant pilot John Blackthorne — sounds like in real life. Instead of playing Blackthorne as a straight hero, Jarvis imbues his Shōgun with an antique-sounding growl that will remind you far more of his former Peaky Blinders co-star Tom Hardy than, say, Richard Chamberlain‘s take on Anjin-san in the 1980 version of Shōgun. It’s a choice that makes the FX show’s central European protagonist feel equally as strange and foreign to our modern English-speaking ears as the show’s Japanese-speaking cast.

Ironically enough, Cosmo Jarvis originally wanted to go even bolder with his Shōgun voice. When Decider sat down with the Shōgun star ahead of the show’s panel at Winter 2024 TCA, Jarvis explained that the genesis of John Blackthorne’s distinctly gravely manner of speaking was, well… “It’s a long story.”

“I tend to look at projects very literally. I take the subject matter literally,” Jarvis said, before explaining that Shōgun‘s 1600 setting made research a bit tricky. “It’s a difficult area to research because only very serious professionals actually research historical linguistics. And I was able to find out that English as spoken in 1600 wouldn’t have been understandable by you and I. So that was out.”

Nevertheless, Jarvis was undeterred. He wanted to do his very best to make John Blackthorne sound like a man of his time. “So I tried to find something old-er. Not 1600s old,” he said.

“I was able to find some old recordings of a sailor from like the 1930s. He’s from England and I liked his voice. His voice sort of had this wispy, high, very high, quality to it and it felt like a relic. And so I experimented with that.”

At this point, Jarvis felt that he was closing in on Blackthorne’s voice. However, shortly before filming, he bumped into showrunners Justin Marks and Rachel Kondo in Vancouver (where all of Shōgun was shot). At this point, Jarvis was already speaking in Blackthorne’s voice…and there was a bit of a note on the “wispy” tone he was closing in on.

“Rachel said, ‘Is that the voice?’ And I said, ‘Yeah,’” Jarvis said. “And she said, ‘Lower.'”

“So then I threw away everything I’d done and I reread the script and I had to basically accept that the script demanded that Blackthorne was a certain — he fills a purpose within the script.”

Jarvis also used his reread to come to terms with the fact that the script itself, written in English (before being translated multiple times in Japanese), wasn’t historically accurate. For instance, most every instance in which you and I hear English, the characters are supposed to be speaking Portuguese.

Jarvis eventually found himself modeling Blackthorne’s voice not on sailors of the distant past, but after his own father and his contemporaries, giving the finished product a personal touch he never intended.

“My father was a merchant seaman and he knows everything about the sea,” he said. “In some weird way, I’m sort of playing my father. He speaks with purpose and clarity and I feel like his voice sort of suited the island that Blackthorne has come from.”

So if you find yourself watching Shōgun Episode 3 “Tomorrow is Tomorrow” this week, wondering where Blackthorne’s voice is coming from, it came from a ton of research, work, notes, and ultimately, actor Cosmo Jarvis’s own father.