In the Creation War (1486 DE - 8777 DE), the Tharagians served as workers and builders under a Creationist named Danzar-Khâl. They built fortifications, depots, and other structures to defend against the primordials and their minions. One of the most notable places they helped build is Aphalur.
In the God Era, a number of great angelic heroes became Higher Powers. When this happened, they were forced to abandon the Mortal Systems. Danzar-Khâl's departure to Nawenglorûs left Tharag (and his other people, the Akthol) to make their own way in Bal-Kriav's Ušuškad highlands.
Both the Akthol and the Tharags claim to be the first dwarven peoples put on Bal-Kriav. They claim a Plaques of Aphalur (c.f. Scroll of Dawn), found at Aphalur, is written in Dwarven and bears the mark of Danzar-Khâl and reads similar to the lines from a Scroll of Dawn:
The first dwarven people of Bal-Kriav are the Akthol and the Tharag. They will serve as my guardians of Aphalur and other angelic bastions of Ušuškad.