The Act of Solace was meant to address the growing problems from casters sickened by the Shards of Zolgar, the after-effects of casting magic. Its main effect was to cause all casters to become property of the crown.
While hardly a major war by most standards, this conflict over water rights brought up questions of ownership of natural resources. It also ended with the destruction of Kubara.
Magic erupted in a fearsome explosion, rending the earth, sinking mountains, and raising seas.