The Shadowmasters is a thieves guild that is based in Telflamm, but is also active in other areas of Thesk. They have existed since somewhere early 13th century, but mostly as a band of petty thieves. Around 1310 the guild became more organised and adopted the faith of Mask, who promised the members dark powers. With this tranformation the guild became more evil and started to become a nuisance. Only that changed in 1368 when Minas Defrout became the new leader of the guild. He transformed the guild to defenders of the city and Thesk and showed this to the public in 1372, when he organised an action against the Sharkjaw Pirates that destroyed them in one night.
Since then the Shadowmasters are seen in a new light. Quite unlike one would expect, in the past years, they have helped reduce thievery rather than expand it. And also helped protect many merchants and the Golden Way. By now they are commonly seen as the protectors of Thesk and are smiled upon rather than feared as they once were. They do still use their power to exort the people, but that is seen commonly as a necesarry ways of paying for the protection they offer.