Re: What are the problems with the "A song of ice and fire" series?
They did rebell on their own, just later. They probably thought that Robert was a weak King, and everyone else was weakened from civil war, so they could go back to their raiding ways. Robert was King already when that happened, and he and Ned put them down. That's why Theon Greyjoy, the last male heir of Greyjoy, is Stark's ward.