Follow Up to the Blue Mountains Question - Gundabad

[Inziladun]

Originally Posted by Kuruharan

Actually, the Iron Hills had been inhabited by the Longbeards since the First Age according to Of Dwarves and Men

I was going off information from Appendix A.

That begs the question though, that if the Dwarves had been established in the Iron Hills for so long, why was it only in the Third Age that they settled Erebor?