Humans can never live in harmony with themselves. They will always attempt to dominate their neighbors. Unfortunately, their last war nearly destroyed their homeworld. The last remaining humans formed a temporary alliance and made their way into the world of Esperia for a new beginning.
Regrettably, human nature cannot change. No matter where they go, they will always create conflict. That conflict spilled into the world of Esperia and started another war that divided the world into two different factions. It seems the problem is not where humans live – it is the humans themselves. You can take humans from their homes, but you can't take the need for conflict from humans.