Dumat was the most powerful of the Old Gods, known as the Dragon of Silence for the vows of silence undertaken by his acolytes. Chantry lore claims it was he who taught the first magister, Archon Thalsian, the powers of blood magic. It was Dumat's followers who are believed to have entered the Golden City, thereby corrupting it with their presence.
Modern scholars question whether the Old Gods were truly gods, or whether they were merely a more advanced species of high dragon, possibly capable of magic or speech, that were worshipped by the ancient Tevinters. Whatever the truth of his history, Dumat was also the first of the imprisoned Old Gods to have been discovered by the darkspawn and thus transformed into the first Archdemon, the monstrous force behind the First Blight.
—From Tales of the Destruction of Thedas, by Brother Genitivi, Chantry scholar