" if Mr and Mrs Viking had a daughter who then married a local the original viking mothers mitochondrial DNA would be passed on "

this is a curious point - if we except the Danelaw (where anglosaxon and viking intermingled, eg Yorvik) what strikes me is the amazing isolation that the ancient Britons seemed to suffer from (even until very recently). It's like two different countries in one. Wales has shown to be (quite obviously) the most 'native/non-saxon-viking' area (excepting the borders where possible numbers of Saxon settlers arrived through the centuries). And that's what's so fantastic in Ireland too. The Vikings were in Dublin as well, yet, it is quite possible 'each one to their own' was the motto, a bit like colonisers in the XIXth century. It is also usual for the vikings to take their own women and, being of an entirely different culture, they may have been happy to just trade, as DNA research shows. But I still wish there was more investigation into the legacy of viking culture and faith in the British Isles and other places. Striking too in that report how Scotland and Southern England contained the same amount of non-saxon (ie.ancient briton) genes. Which goes to show how wrong we are when we think population movements always involve extermination and/or mixing. After all, King Arthur was fighting an enemy (i.e. paradoxically, the 'English', ie. the Danelaw). And you don't usually marry the enemy's daughters, or if you do, it's in isolated circumstances. eg for political reasons.

My point is, when we go back in ancient history, there's so much that is so revealing (clearly so evident in isolated mountaineous areas for instance still today). Even though cultures have superimposed one another, a native Ur-ancient tradition must have remained in folklore and in our collective memory. That unseen tradition really interests me, hence the purpose of my other thread 'rub your arse'.