The Capital of Cardolan

[BGreg]

Originally Posted by lindil

The Dunedain were very much preservers, as far as they could, and Tharbad had been established as an early 'crossroads', never thought about the math that puts it's final abandonment to bilbo's 21st year - excellent data point.

It would have had ancient buildings, close[r] contact both with Gondor, Rohan and even the more civilized Dunlendings and was probably 'The City' for all the wild lands surrounding it - even maybe for the Druedain fisherfolk on the coast , so it almost certainly was the chief city if not outright [if such things needed to be formalized] 'capital'. By Bilbo's day it would have been the ONLY Numenorean inhabited City/Town in the North that was not secret.

I don't think that Tharbad was populated by Numenoreans anymore by the time of Fell Winter. They probably all died centuries ago, and were replaced by Dunlendings. How did that happen? Their bloodline was mixed with the blood of the lesser Men, and slowly turned them into 'ordinary' Men, completely oblivious of their descent. Unlike in Gondor, which was well populated, here the Numenoreans would have very little contact with strangers or other Dunedain, and would have been forced to breed with lesser Men to survive. So after centuries of life in fear, they would have consisted primarily of Dunlending Men.
So, the last remnants of Tharbad were actually only abandoned by those Dunlendings, who then went south in pursuit of a happier life, safe from cold winters of the North.