There was no-one who could play evil like Peter Cushing, but it was always charming and polite; it was gentlemanly evil; it was British badness delivered with charm.

The message was: being wicked is no excuse for bad manners.

Look at Star Wars, in which Cushing plays Darth Vader's boss Grand Moff Tarkin. His performance is a stunning example of cut-glass badness, particularly when facing off with Princess Leia. "You don't know how hard I found it, signing the order to terminate your life," he says. All she can hit back with is something lame about Tarkin's foul stench. In reality, says Carrie Fisher who played Leia, Cushing smelt like linen and lavender.

And that was his secret: charm delivered with the slash of a knife. You can see it in another of his less well-known roles in the Hammer TV series in which he played a former Nazi commandant in hiding. Brian Cox plays one of his victims and Cushing delivers a performance that could turn down the room temperature.

He could play the good guy too. Check out his Winston Smith on youtube. Cushing played Orwell's hero on TV in 1954 and the scenes in which he is tortured are still upsetting. Tormented and exhausted, he is strapped to a table. "How I can help seeing what's in front of my face: two and two is four," he tell his tormentor. "Sometimes," replies the torturer, "two and two is five."

It's a moving, modern performance from Cushing, but a largely forgotten one, although this is the year to change that. There are two new books about Cushing out soon and preparations are being made for an exhibition to mark the 100th anniversary of his birth. It will be a celebration of a fine actor, but also a great skill: to be evil and charming at the same time, to look like your grandfather but act like your worst nightmare.