I too had an inordinate amount of Scandinavian DNA in my results 79%. Given I don't have knowledge of any immediate ancestors from that part of the world, I thought it was wrong or my results were someone else's results. I know my family history is English (VERY HEAVY - most of my research would indicate 90% England)/Scottish (some)/Irish (small)/German (even smaller)/French (just two in 400 years). However, after doing a bit of research it's not as far-fetched as I first thought. I'm very heavy on the English side with both sides heavily represented on the family tree. In 500 AD, Ageles, Saxons, and Jutes invaded England and stayed...all these "tribes" are from what is now Denmark (Scandinavia) 300 years later another group of Danes (with a few Norwegians)...this time called Vikings invaded England again and stayed...in fact the Danes controlled most of England for almost 100 years. In 1066, the Normans invaded England...the Normans were originally from Denmark. So, if someone has "British Isles" DNA, it must mean they were Celtic or Britton-Roman. After this research, I don't think it's too far-fetched at all to have very heavy Scandinavian DNA...given the fact that England was invaded, occupied, and colonized by Danes/Norwegians from 500 to 1066 AD. Almost 600 years of invasion and occupation...all that DNA must have been passed down. I bet a lot of English can trace back to the Danes who colonized...and quite a few Irish/Scots can trace back to Norwegians to colonized there as well. This story isn't unique...this happened all over Europe and the world...our DNA goes back thousands of years...who really knows where there ancestors were living in the year 20bc or 350AD.