The Principalty of Erenian was a human-grey elven realm in the east bank of the Osorio river, Aels, in the northwest of the Barlans region. It was alternatively a vassal state of Sargos, Tardos and Degoland.
Traditionally a contested region, from where will be launched several invasions by the peoples of the Barlans to the Five Kingdoms of the Northwest, with the Weseurian expansion and the consolidation of the western bank of the Osorio as a defensive border for the Five Kingdoms of the Weseuros, the Sargonic expansion of Martin the Conqueror (2234-2297 a.a.H) led to what was seen as a natural expansion to the eastern bank of the Osorio, to use the rich agricultural lands and as well, to serve as a buffer state, a frontier between the Five Kingdoms and the peoples of the Barlans.
With a rising humanism in the Five Kingdoms, there was a growing pressure among the Grey elf population of the northwest of Aels, which as well was confronted with the aspirations of their allies, the High elves of the Empire of Whide Axis to rule over and protect the aelian elves.
With the foundation of the River Guard first along the western bank and the campaigns in the Barlans of Martin the Conqueror, that helped to pacify the region, the expelled Grey elven population of the western Bank of the Osorio by the River Guard, the pressure of the Whide Axis and some anti-elven reactions in human cities directed against grey elves of local elferies, was decided by the Sargonic King Martin the Conqueror, to create a principality on the eastern bank of the Osorio, a region of colonization to settle down Grey Elves, in an attempt to segregate them from humans, but as well as a measure of protection of the same grey elves, which was seen as valuable artisans and tax payers by the crown -in difference to some local nobles.-
At the same time they were attempting to form colonies and new elven-human realms in conquered Polforia, they did the same in the region of Erenian, a highland and mountainous region in the northwest of the Barlans:
Originally to be a solution to provide a safe home for the grey elves who were expelled for security reasons of the Western bank of the Osorio by the River Guard and to provide a relief to the crowded, walled Elferies into a Grey Elven state -under human tutelage-, some nobles and cities of the Northwest used the existence of a grey elven state as an excuse to forcefully expel Grey Elves from some human cities.
There will then be an important migration -voluntary and forced- of Grey Elves to Erenian.
However, while much of the idea of the creation of grey elven communities away from humans was to segregate the populations, parallel with the elven migration there will be an important, non-official human immigration -many cases, of escaped serfs-, that settled along with the elves, creating the human-grey elven identity of Erenian.
Erenian, founded with the same impulse that the colonies human-elven colonies of Polforia, suffered as them of the withdrawal of support from the Empire of the Whide Axis, who after the disappearance of their Emperor focused more and more towards Ushaenor rather than imperial ambitions. As well, tensions and conflicts among the human realms will mine the closer support they had in the Five Kingdoms, especially as Martin the Conqueror grew older and couldn't anymore ride with his sword and his armies to bring fear to his enemies, began once more time raids of the barbarians of the Barlans to the settlements of Erenian, which lacked a strong defense.
The River Guard was tasked to extend their operations to the eastern bank of the Osorio, the defend Erenian, but the range of their actions was only near the rivers, and the garrisons and fortifications to the order often wouldn't protect the hinterlands of Erenian: this was an important setback for the expansion of the colony.
(raids of the peoples of the barlans, lack of defensive capabilities. Demography)