For designing clothes fit for kings—not to mention queens, night's watchmen, and wildlings.

Michele Clapton won an Emmy for the medieval-flavored costumes in HBO's Game of Thrones, which have inspired fashions at Valentino, Helmut Lang, and Derek Lam. Between seasons she works on film projects, such as Werner Herzog's Queen of the Desert—about the life of writer and explorer Gertrude Bell (due out in 2015)—and the Memento-like Before I Go to Sleep (out this fall).

Fast Company: Game of Thrones is based on books about a fictional world, so you must have had a lot of latitude when creating the costumes. Clapton: I love the freedom of Game of Thrones. Developing the visual sense of the character— that's the essence of all costume design.

The show is set in various far-flung locations, and you make individual collections for each region. How does that process work? I create the visual rules of each area. I'll draw sketches to represent each area based on what [materials] they have available, the transport, the climate. I work with the production designers to see what the architecture is. I think that is what's successful about Game of Thrones: It's not just fantasy for fantasy's sake. You can almost imagine that it was real.

But because it's not historical, nobody can fact-check you, right? A lot of the book [readers] do. Whenever you read a book, you have images in your head of how people look. And then someone comes along—in this case, me—and designs, and it's not what's in your head. People react to that. But I don't worry because it's our version and that's all you can ever do.

In Before I Go to Sleep, you dressed star Nicole Kidman in modern clothing. In contemporary films, the clothes are so often not noticed. That's almost the beauty of them—they have to tell the story without being celebrated. Sometimes that is the hardest to do because everyone thinks they know clothes

Fast Company