It is thought that The Salamander’s Guild was initially empowered to break the power of The Buildengands from the inside – and break it they did, eventually. The last of their power was broken after The Sundering (CY 5000) caused a great disruption, leaving only regional crime syndicates, “guilds” and gangs.
At one point, the guild, using ancient eldritch power, created items it tried to use to bring together all criminal organizations under their power. It failed. These items were destroyed, few are left such as Rings of Holdout.