Ooh, I dunno...Take That could work well for the Saxons and maybe even the Vikings. Consider:
Back For Good (Song celebrating the Viking Danelaw)
I Found Devon (Saxon song; lyrics slightly altered )
Pray (including backing by the Lindisfarne Monks (but no guarantees against attacks)...)
Promises (Saxon Lament on Viking integrity...)
Reach Out (Viking raiding song)
Relight My Fire (Old Saxon and Viking camping song)
It Only Takes A Minute (another Viking raiding song)
And of course, my personal favourite...
Rule The World (the Wessex national anthem)