THE WARS TO START ALL WARS

[Sunray]

"...the catalyst that..." Nope. The assorted tribes were fighting each other and various invaders long before Lars and Sven decided to go for a boat ride.
Boudicca was fighting Rome in A.D. 60 or 61. Julius Caesar invaded Britain twice: in 55 and 54 BC. The Celts drifted by between 2000 BC and 1200 BC. The Anglo-Saxon's around 410 AD. The Norse were late comers.
"...does not even resemble how we spell it..." Isn't The Queen's English. Or any other kind of English. Spelling in the Dark Ages wasn't an exact science anyway. Getting that way again.