The question touches on a tricky one because 'The Book of the Unknown Vikings' isn't a title that rings a bell in mainstream Viking fiction. It might be a lesser-known work, a self-published novel, or perhaps even a mistranslation or misremembering of something like 'The Long Ships' or a saga collection. Without a confirmed author or publication details, it's hard to pin down the exact cast. Usually, in narratives centered on 'unknown' Vikings, you're looking at a core group of explorers or outcasts. There'd likely be a seasoned chieftain or ship's master, burdened by past failures or seeking a final legacy. A younger, hot-blooded warrior, maybe a second son with something to prove, often serves as the audience's entry point. You'd almost certainly find a cunning shipwright or navigator, the kind who reads the stars and weather in a way that feels like magic. A skald or lorekeeper might be part of the crew, there to record their deeds (or lack thereof) and provide the mythic texture. If it's following common tropes, there could be a shieldmaiden defying her clan's expectations, or a captured Christian monk whose worldview constantly clashes with the Norsemen's. Their conflict wouldn't be with famous historical figures, but with the elements, ambiguous encounters in Vinland, and internal power struggles on a longship confined by the open sea. The 'unknown' part suggests they're intentionally outside the sagas of Ragnar Lothbrok or Harald Hardrada, so their personalities and frictions would be the main event.
I tried searching online communities and book databases, but hits are sparse. Sometimes these titles are alternate covers or translations for books like 'The Last Viking' or 'West of Eden'. If it's a more recent indie fantasy, the characters might have modern sensibilities layered onto the historical frame. The key would be how they handle the discovery of a new land—does the navigator see it as a prize, the chieftain as a burden, the young warrior as a chance for glory? That dynamic would define them. Until we can track down the exact book, talking about Hasting or Bjarni feels misleading. It's a reminder of how many stories are out there, just beyond the main trade routes.