This arm ring binds you in loyalty to me, your lord. Your chieftain. Any oath that you swear on this ring must be honored and kept.
But like every time I see Vikings stuff floating around where it’s like “friendship bracelet” I fling my hands up in the air! Because it’s not a friendship bracelet! It’s not like a “oh I like you so much, my special friend” gift. It’s a ring. Like, the whole notion of being a good lord in Norse and Anglo-Saxon culture of this era was centered around the giving of rings. Literally the term “giver-of-rings” in Anglo-Saxon refers to a king or lord. This is particularly on my mind, because last week I was working on a passage of Beowulf in which the example is given of someone who was a bad king, and the reason he was a bad king is that he failed to give rings. So part of this exchange is, like, Ragnar demonstrating that he is a good lord— not only to Athelstan, but to anyone who might need to be impressed or reassured that Ragnar is a giver of rings.
Also, the relationship implied here is not one of friendship, or bromance, or even of loyalty as we would understand it. It’s a relationship of profound mutual dependence: Ragnar has the right to make demands of Athelstan, to command him, to control his behavior in certain ways, and Athelstan has the right to expect, basically, sustenance from Ragnar: to expect protection, shelter, and a share of wealth.
All of this is so cool! And I don’t even like Vikings! I guess it seems less interesting to me, and kind of disappointing, if the ring gets treated like either a special friendship gift, or else as like the special badge of Ragnar’s army.