Game of Thrones' dark and cynical interpretation of the Middle Ages is a huge problem. The creators argue that it's a more-realistic version of the Middle Ages, but just because it's edgy, doesn't mean it's real.
George R.R. Martin wants to have his cake and eat it too: he claims his breakout hit fantasy series is based on real history, but hand-waves away criticism of his approach to issues of race. Part XXXV in Race, Racism and the Middle Ages, by Shiloh Carroll.