Reading up on history and relating it back to Game of Thrones can be a bit depressing. One example is the
Harrying of the North. After William the Conqueror took over England, he got sick of all the Anglo-Saxon/Danish rebellions in the North and basically marched his men up there and destroyed everything, women, children, whole villages, crops and livestock. The Domesday Book a few years later described parts of it as "wasteland".
Did the North ever get revenge against William? Did anyone? Nope. Shit happens I guess, the "bad" guys often win, and most never get what they deserve.