River of Stars
The Thundering Wars is the name given to a (relatively) short civil war among various factions of the giant races deep underground. Politically, the giants had long formed themselves into guilds, called collectively the Pillar Guilds. The Thundering Wars were ostensibly between two key guilds and their allies: the Plainwatch and the Rootwick. The confrontation was also, ostensibly, over power and influence within the Arches. But it is also felt that the confrontation may have also been over efforts to quell a growing religious movement among some giants.