Oswald Mosley

Oswald Mosley arrives in Birmingham as a rising political star, aristocratic and immaculately charming, courting Tommy Shelby's influence and money for his new party. He speaks in smooth, reasonable tones about order and national renewal, always smiling, always watching, a man who wants power and has worked out exactly how polite ambition can look.

Claflin plays him without a trace of cartoon villainy, which is precisely what makes him unsettling — the charisma is real, the manners genuine, the menace entirely implicit. The show trusts the audience to recognise the danger dressed as civility, and Claflin's control, that unbroken pleasant surface, makes Mosley one of the series' most quietly frightening additions.