He is best known for his roles as Copenhagen mayoral election candidate Troels Hartmann in the Danish police procedural The Killing, the character Charles Augustus Magnussen in the third series of the BBC programme Sherlock, fictional Russian president Viktor Petrov in the American political thriller TV series House of Cards, the mage Stregobor on the Netflix series The Witcher, and Grand Admiral Thrawn in Star Wars Rebels and Ahsoka.