Comment by CRConrad

> Isn't it a historical fact that the eastern and western roman empires used "barbarians" in their armies?

Yup.

> If the vikings fought for these empires, then why not the anglo saxons and other germanic peoples?

That's not even in question any more, it's also a historical fact.

The Varangian Guard in Constantinople started out, as the name implies (or at least used to imply[1]), with mainly Swedes come down via the Rus rivers, but a century or three later was very mixed with Franks and Anglo-Saxons, and towards the end may have consisted mainly of the latter.

[1]: I was taught, in history class in Sweden looong ago, that "Nordic raiders faring west from Norway and Denmark were called Vikings, and those faring east from Denmark and Sweden were called Varangians." But given that the name 'Varangians' seems to come primarily precisely from the Byzantian Imperial Guard, maybe the definition should follow that, and acknowledge the shifting ethnic composition of their origin.