Upspring

Nearly right after the appearance of Shimmergloom in The Mithral Hall the dwarves of the Ironfoot Mountains rose up against their King, Kiv Ungart, and deposed him in favor of Clan rule, starting The Mror Holds.
Shimmergloom's appearance was more of a catalyst, as opposed to reason, for the start of Upspring as the greed of the king and lack of interest in reclaiming The Mithral Hall stirred the hearts of many dwarves. The insurgents, favored by the populace, stormed Palace Ungart and killed the King.