What we know of the Dweorhians comes from the ruins south of the Wall, back when their Empire came nearly as far south as ours does. We've no idea what caused them to retreat back North and build the wall, its certainly a curious question...Lets hope we don't suffer a similar fate... — Vibius Modius Musa Imperial Historian
The Dweorh people who dwell North of
The Wall are an absolute mystery to the Empire, the only things known truly are that their Empire was as big as the Imperials. At some point however they retreated north and built the wall, encompassing their lands and halting all trade and even diplomacy with any other peoples.
The information we know about the Dweorh has come from the ruins they have left behind, a motley collection of burial pyramids, old temples and former settlements. We know that they believe in a different set of Gods than the Imperials do and that they at the point of abandoning the settlements had a similar level of technology that the Imperials currently have.
Some translated writings have talked of a great cataclysm that came across the land and it speaks of the gods descending the sky causing destruction on a grand scale. Imperial historians who have studied these writings are unable to reach a consensus on whether this means a literal invasion from the heavens or some kind of plague or famine. Either way it remains the subject of vigorous debate to this day.
It is noted that the images depicting the Dweorhians show them to be fairly tall beings with dark skin, this does not gel with any observed peoples on the Wall itself. The architecture of the wall and the design elements are consistent which leads the Imperial Historians to believe the ruins are related to the people on the Wall. Attempts have been made to send letters to the people on the Wall however nothing is ever returned.
They remain a great unsolved mystery, the Empire has tried to letters, returning artifacts and books found in the ruins but nothing seems to illicit a response.
Interesting way of folding the Dwarves into your classical world, and I too am curious of this mysterious wall...