The Fanged Kingdom dominated the Jungle of Fangs from about 1000 BC until roughly 300 BC. The gwerin masters, believing themselves the heirs to the ancient aelvar empire, broke off from the Western Empire during the reign of Emperor Primus Aurum, second in the Aurum Dynasty. Scholars believe that they made some sort of deal to provide magical technology involving biological and/or soul manipulation to the Western Empire in exchange for independence, because that was their strong specialty.
The nobles of the Fanged Kingdom were notable for worshiping/revering a serpentine deity known as the Rainbow Serpent. In its image, they modified many of their servant peoples (humans and lesser gwerin) to have serpentine traits. From those experiments sprang the Ophidian race and the serpent-kin culture. They also implanted hereditary, genetic commands that still affect the culture in the Jungle of Fangs, such as the castes and the restriction of the color blue to the noble caste (who were the descendants of the overseer caste).
In approximately 300 BC, the last of the rulers made a pact with the White Skull in which they would provide a never-ending supply of worship to him in exchange for the knowledge and power to apotheosize and become deities in their own right. To fulfill their end of the bargain, they implanted a genetic command to worship the Queen Ascendant, who was the daughter of the last king of the kingdom. Acting on the knowledge they received in exchange, the masters carried out a grand ritual on their mobile fortress palace, Ar Dolema and disappeared from history. Did they ascend? If so, there is no record of them. Did they botch the ritual and destroy themselves? That is the consensus of most scholars. Others believe that they entered a closed demiplane or that one of them betrayed the others and ascended alone, dooming the others to oblivion. Yet others believe that they ended up in the Abyss as punishment for their horrific crimes.