Who are the 'wild men'?

[Elmo]

Originally Posted by Inziladun

Nice enough that many of the Dunlendings and their kin had removed to Eriador to become willing subjects of the Northern Dúnedain settling at Bree, and going so far as to abandon their former language and customs.

I'm sure the Dunlendings migration happened in the Dark Years of the Second Age, where they moved North to escape Sauron's shadow and so long pre-dating the establishment of Arnor.