Velth, City of Traitors

From the introduction:

Long ago, in a war forgotten by even the most learned bards, a king called upon the mountain city of Velth to assist in battle. However, the citizens of Velth had become powerful and wealthy and had much to lose, so, believing victory to be impossible, they turned against their king and countrymen at a pivotal point in the war, barricading themselves in the mountains and abandoning their oaths of loyalty.