My mining family came from the NE, Gal's neck of the woods in fact, but I knew that as my G Grandparents were still very much alive when I was a child - they had moved to the SE during the depression and raised my dad so I knew them very well
What we didn't know before my friend's efforts is that some of these miners, although by no means all, had originally come from Northern Ireland (Derry) and then to Durham via Scotland!