I am a fan of Amon Amarth. I've seen them twice live and own several shirts and albums by them.. Have listened to them for over 6 years.. The viking age started in 793 CE with the invasions of Lindsfarne, and ended around the year 1200 CE. If you're talking about northern people of indo-european descent in general, they believed their mythologies and folklore to be a part of their history which spawned back much further. What we know of their mythology/history was passed down by word of mouth and written in the runes. What we know of the runes was passed down in the lore and rune poems. From the Havamal we know Allfather Odin had won the runes through his sacrifice of himself unto himself thereby giving birth to the ancestral culture associated with them. The gods were viewed as senior kin, as ancestors who were mortal and would die. They were immortalized through their deeds, as anyone who had the courage and honor to die in battle to preserve their way of life. Our ancestors lived their "history" through their "mythology".