A Longship Tale

A true Viking lie. The kind that were told repeatedly on long voyages by Oswald The Scar Faced who had a lie for every scar he bore went something like this.
Many's the man that has asked me how I came by the name Oswald. It is a wonderous story both to tell and to hear.
My mother named me Dagny, a name I was proud to bear and did for many long years till I chanced to meet a man of dubious decent along the coast of Serkland who challenged me to a Flyting duel.
I of course being the master of Flyting that I am accepted and we both swore to take the other's name if we lost.
Him being the challenger I went first.
Oswald the great as they call him of late is a master of Flyte no denying. Though he looks hale and hearty and his words are quite arty his wit can be called only farty.
The laughs I got all around were pleasing to hear and we all drank many more tankards of mead. Then Oswald stepped up belched and retorted.
Dagny dost claim his Flytes bring him fame and that doubtless is true where he comes from But Vikings it's known when so far from home use words that are nothing but coxcomb
Now those were words a man cannot bare anywhere else but in Flyting. I had to agree with everyone there and admit that he had bested me.
So I took his name along with his head. No point in both of us suffering.