The Teir'Dal were an elite elven military unit. This caste of dal bore the Elvish word "teir", meaning "dark". This was to denote not only the black uniforms they wore, but their techniques of stealth, as well as their almost sinister devotion to duty. By tradition, this unit has been commanded by the second-in-line to the Thex throne. During the Dragon War, they were led by Prince Keramore Thex. They were considered loyal and courageous and they remained dutiful even when facing deadly threats.
Origins of the Teir'Dal
During the War of Plagues, the seat of House Thex, a keep they called Neriak was overrun by a tribe of goblins serving the Plaguebringer. A dal captain named Mathus T'Vyl led a band of his most skilled fighters into the besieged capital and rescued the Thex family, who had been taken prisoner. So grateful was Queen Thex that she promoted T'Vyl to general, and bid him to found a new order of elite soldiers called the Teir'Dal. The order was placed under the charge of her son Donal Thex, a skilled combatant in his own right who was second in line to the throne.
Former Teir'Dal Commanders
Historic Events involving Teir'Dal
Siege of Toskirakk
Formation of the Ashen Order
Transformation of Keramore's Teir'Dal
Time Period: Age of Exile
When Keramore Thex's Teir'Dal were chased by the Dragon Army in the ruins of Quin'Sari while trying to distract them from the Exodus, they discovered a Spire deep beneath the city. The portal was opened by an amulet carried by the Prince allowing approximately five hundred of the Teir'Dal to pass into the shadowy realm of Umbra in order to escape the Dragon Army. 
While in Umbra, this group of elves were exposed to certain influences which brought out the latent essence of the Dragon Knights, causing changes in color and the growth of horns. When Keramore's forces returned to Norrath, the new races were terrified of this new race with "dragon's blood", who were called the dark elves.