The show is based upon a book series called A Song of Ice and Fire by George R. R. Martin. It's an epic fantasy series that follow 7 different kingdoms on the fictional content of Westeros. Essentially, the first two seasons deal greatly in who is to be ruler of the realm. (The realm being Westeros) so you're seeing 7 different kingdoms going to war. Hence the name, Game of Thrones. But it's far more than that. I just don't want to give too much away.