Game of Thrones is great. One of the reasons why it's so great is its unpredictability. It subverts tropes, messes with your idea of heroes and villains and generally does a tremendous job of keeping its audience guessing.
Why is that? Probably because so much of it borrows from actual history. And history doesn't follow a plotline, history does whatever the hell it likes.
This video does a great job of illustrating just how much Game of Thrones takes from historical narrative, and I think it's super cool. It adds a real air of legitimacy to the show. It grounds the show in ways we're not used to seeing (in television particularly).
Well worth watching.