There is some cursory stuff in the Sun King
history quest line, but it's focused on the tribe that followed them and how he betrayed or didn't betray certain clans.
There is a main story
quest line for those who want to learn more about the
history of Resonail (as well as a good way to start leveling up your team), but that is mainly for those who may not have access to the online multiplayer portion which is really the meat of the game.