Northymbre Faction Symbol Replacer
This simple mod makes use of the Raven symbol already present in the game for the invading Viking factions to replace Northymbre and Northymbre Usurpers symbols, though recolored to match their faction colors. This symbol is fitting because it was the symbol of the Danelaw. [en.wikipedia.org]
I felt that the playable Great Viking Army factions having crosses as their faction symbols, made it seem that the Danes were more devout Christians than their Saxon counterparts!
ALTERNATE VERSION: