This is an in-depth study of the origins of the Scots, the Picts, the Britons (and even some Anglo-Saxon history) in the Dark Age period. It is a little bit controversial, but I think it is a reasonable assessment. Even if you don't accept the conclusions, hopefully you will appreciate the work that has gone into it, and the presentation of the evidence from their own legends and testimonies - you are not likely to find many of them in other history books. At the very least I hope it will be a starting point for many people to revisit the past