The “Lost King” is a semi-mythical figure often considered as the first true Aergosian. A common figure in Aergosian ancestral worship (as the “King-father”). Historians largely assume that Aergoth itself is a variation or the Lost King's actual name, which was lost to history.
The main conclusive facts of the Lost King are that he led the first humans across the ocean to Idryllia, unknowingly triggering the Primordial Wars. Legends of his actions during the wars themselves vary, with some insisting he remained at home to govern Aergoth while others paint him as a war leader and hero. The most potentially accurate tale is kept by the Knights of Alestraxia, who claims his heirs amongst them, and suggests that he was slain in earlier battles with the Primordial Baelgar and the Beastmen (Others include the Scaled Folk, other Beastmen, and the climactic battle alongside Alestraxia herself.)
His burial site remains unknown, and given the convergence of Ancestral Worship with Revenant creation, it is possible that the Lost King may have re-manifested in the physical world through the power of his worshippers, though likely entrapped in his tomb.