Bizantine princess Anna Kannana writes about it and she calls them Celts which I think is wonderful because then we're recycling these old names again. She basically describes it as this irresistible force that these Celts have initially but that if you can withstand that it diminishes. Once they fell to the ground with their big shields and their heavy spurs they lost their impetuousness and were vulnerable so this to me shows more of a style of fighting than something specifically Viking. historian and Viking expert neo-price who wrote the children of Ash and elm says much of what's portrayed as Viking styles of fighting are based on tenuous information.