In 862 HE, three centuries since a massive illithid invasion drove them from their home world, four Helas Vessels pierced Bal-Kriav's atmosphere. One of these primordial arks landed in the Mirtheon sector of Bal-Kriav's Grashakh Region. The then-called Svoghast Helas, a void ship constructed by the primordials for planetary invasions, was under the command of the mortal Krak-Oth. Under him and his Durkoth people were the subjugated Theegan of Horgon. Their initial major settlement on Bal-Kriav was Argruxiel. Advanced and well-organized, its Theegan slave army veterans of bygone wars, Krak-Oth's yoke spread to the goblin and troll tribes of northern Grashakh and southwest into the Tribe Steppes, a land once silent to the threat of the Jara. Ten years after the founding of Argruxiel, with free and subjugated villages and outposts extending for three hundred miles westward, the Ak'mrîtun Empire was founded, with Emperor Krak-Oth as its first leader.
In the year 1001 HE, the empire's resplendent western gem, the city of Binê Sadôr, was selected as the new seat of power. From this novel capital, Emperor Krak-Oth presided over his domain, while his most trusted lieutenant, Orthraak, administered the eastern interests from Argruxiel.
Between 1100 HE and 1200 HE, the Durkoth of Ak'mrîtun underwent significant transformation, joining the Durkoth Descent (995 HE - 1355 HE). They became increasingly aquatic, abandoning the surface for the dark seas of Cthorgo and the Green Nebulous. On the surface, lands once ruled by the Durkoth became the spoils of their former subjects. Argruxiel fell to warring bands of goblins and trolls, while the western gem was claimed by the Theegan. The empire's eastern interests, located across the Giant Steps, were gradually lost. However, the empire persisted in the east, centered in Binê Sadôr.
Early in the First Epoch, zoolatry gained prominence in the empire's northeastern frontier, the mining towns of Arirmarg. Greatly offended by this, on 13 Saunas 43, the god Krak-Oth cursed these horse cultists. They awoke the next day as centaur abominations, the first Jara. Driven by rage and a penchant for destruction, they ravaged the empire they once served. Places not overrun were in a perpetual state of siege. Most of Ak'mrîtun's people fled to the Northern Hordelands, away from the plains where the Jara reigned supreme. In Year 49, the Ak'mrîtun Empire came to an end. Theegan civilization continued on at Briltarn and Incubus to the southwest and Hazrith to the northeast.