It's probably just the free tech that you got by mistake. I don't think you can trade it with anyone but norse civs. It probably won't do you any good though.
Anyway the turn:
The invading French have been repulsed, and annialated, with the loss of one brave Danish swordsman. I see the French have been busy fortifying their coastal cities.
In a quick raid on London an English swordsman was killed, just to remind the English that we haven't forgotten them.
====>KS