The show and books are set in the fictional land of Westeros. Political scheming and maneuvering for power are at the heart of the story, with the prize being rule over the seven kingdoms on a very uncomfortable "iron throne" (Actually several swords melted into this shape by a dragon). Plus an as yet undisclosed menace from the icy north held at bay by volunteers who man a huge icewall to keep whatever this is from entering the realm of men. Oh, and the return of dragons to this mystical realm after their supposed extinction nearly three hundred years earlier. Lots of violence and sex, so it's not for the kiddies.