By the 2400s, the military balance of power in Ereláe had passed to the nomads-- numerically weak, but highly mobile, every inhabitant a trained horseman and soldier. The civilized states had once been able to maintain large, professional standing armies; but Axunai was splintered into small weak states, and the unity of Caďinas was little more than theoretical. In 2435 the Bešbalicu, another Naviu tribe under the leadership of Ädurunz, occupied the capital, Ctesifon, though they were unable to conquer all of Eretald.
The news percolated to the other Naviu. The anaraz (headman) of the Gelyet, Hiuraz, saw the possibilities, but also saw the besetting weakness of his people-- disunity and impatience. With discipline, he believed, the nomads could rule the world. He preached this idea to the other Naviu; when persuasion failed he and his best men would challenge other bands to fight. He never lost such a contest, and by 2470 he had succeeded in uniting all the Naviu (except for the Bešbalicu, who considered him an unwashed wannabe).
He now called together all the chieftains and recounted the glory gathered by previous nomads— should the Naviu not do the same? Should they not, in fact, amass such glory that Almea would never again see the like? The chiefs agreed.
They concentrated first on other nomads: the Meťelyi, the Bucair. Almost as soon as these were conquered, they were made allies and fellow warriors. In 2476 the combined horde poured into Xengiman, destroying armies, fields, and cities as they went. In 2483 they entered Weinex, carried off all the treasure they could find, then burned the rest— an immense loss to Axunaic civilization.
This was typical of the Gelyet: their invasions were brutal, and their rule was destructive. They burned fields in order to create new pasturage; they saw no use for cities except as sources of loot; anyone who resisted them was destroyed. Unlike the terrestrial Mongols, they did not foster trade or communications across their empire. Their one positive achievement was to spark better organization and military effectiveness among their enemies.
Hiuraz died in 2505; the custom of the Gelyet was to select leaders through the käpinz— a tourney of games and tests of strength. The new anaraz was Länguraz. He destroyed the Gurdagor, who had attempted to regain their territory in Jeor while the nomads were busy with their games. He then conquered the Bešbalicu and the Coruo before turning his attention to Caďinas (which had reconquered Ctesifon back in 2472).
The southern third of Eretald was taken, and the army was besieging Ctesifon itself when Länguraz was killed by a Caďinorian archer. The käpinz was held on the outskirts of the city; but just as Aitän was declared the winner, news came of a rebellion among the Coruo. This could not be countenanced; the Coruo were duly chastised, as well as the Meťelyi and the rebellious Axunemi.
From here Aitän drove straight north, conquering Sarnáe (2536-8). The Gelyet now ruled millions of nomads and perhaps 20 million peasants and urban dwellers, and ruled from the northern to the southern sea, from the Lernukh to Pronél.
As he relaxed in Govanro, Aitän heard news that a rebellion had broken out in Curau. Without hesitation, he marched his army south. Somewhat to his surprise, he found the city much larger: the king of Curau, Rejabriš, had extended the walls into the countryside, encompassing fields and springs. It would be difficult to starve the city out. More annoyingly, Rejabriš had begun a top-down militarization of his people to match that of the nomads— the entire peasantry served as infantry, the nobles as cavalry; even priests and women served as archers. The same system was used in Xiau.
The Gelyet were unable to take either city, nor were they able to prevent a daring Curali incursion in support of Nogali, downstream along the Xengi. The news emboldened other rebels, especially the Meťelyi, rather than beat his head against the new city walls, Aitän rode to fight the rebels— allowing Rejabriš to consolidate his new nation of Xurno.
Over the next decades, the Xurnese exerted their realm, and even (with Sainor help) went on the offensive. Within a century they had effectively cleared the agricultural areas of Xengiman of Gelyet.
With the Gelyet concentrated on Xurno, other enemies saw their opportunities. The Caďinorian emperor Andona reconquered the upper Svetla in the late 2500s; Sarnáe recovered its independence by 2610.
The Gelyet retained control over the Barbarian Plain for some decades; but after a further series of defeats at the hands of the Caďinorians, the other Naviu tribes revolted. In the east, two important pockets of Gelyet remained. As many as 25,000 Gelyet invaded Čeiy— that country's first experience with barbarian invasion— though they were never able to conquer the capital, Ṭetäs. By 2750 they had been pushed into the Ediri mountains. There they remained for centuries; but after the Čeiyu civil war their territory was absorbed by Čeiy.
The other pocket was in the Ctelm mountains, extending into Tyellakh— a rare reverse for the new ktuvok empire of Dhekhnam. The Dhekhnami soon pushed them out of Tyellakh proper, but they remained as an identifiable population in the mountains for some centuries. Finally the Losainor pushed them out of the region, whereupon these remnants of the Gelyet were absorbed into the nearby Naviu tribes.
Ironically, perhaps, almost all the Naviu and many Caizurans as well claim to descend from the Gelyet. Nonetheless, the only remnants of the Gelyet language is Nüedawäši, a strange Ṭeôši/Gelyet creole spoken in Räntsüzôl, the mountain realm based on their old territory adjoining Čeiy.