Good, free, lecture by Mike Copper. There were 10 minutes that seemed a bit waffley, but the conclusion made it relevent. 

Made me think. The pot remains suggest that the Outer Herbrides had 800 years of stable, perhaps boring, peace: which was replaced by conflict. 

The suggestion was made that environmental despoilation may have cause the end of their good life. It certainly was not caused by idiots, believing the evil rich, voting to enslave their own children.