Dragonblades

The dragonblades were supposedly created as a prize from Tiamat to her followers. A sort of reward for completing a terrible "scavenger hunt" - killing important people. There is presumably a blade of each color. 
Sethokesh, The Shard of Daggerspine
Necrotaush, The Pestilent Fang
Haziwran, the Scourge of Amgon'thol
Braugtheros, the Eye of the Blizzard
Anxucotl, the Fury of Sapphiron