The Gwaith-i-Mîrdain(S. "Brotherhood of the Jewelsmiths") was a Guild, school, and workshop established by Celebrimbor in Hollin. This order achieved greater feats of workmanship than any other individual or group in Middle-earth save Feanor — and perhaps Annatar- though the power of the Elven-rings was such that even the One could not truly dominate them.