We have little detail about the origins of these Men, and our earliest specific mentions go back only as far as the first part of the Third Age (when they were said to have acknowledged the rule of Gondor at its height). We do know, however, that Men had passed through this region much earlier - as far back as the great westward migrations of the First Age - so the ancestral Men of the Vales of Anduin may date back to those ancient times.