Forged by Eoferwic from seven iron rods; three hard and four soft.
It took days, yet as the hammering and cooling and heating went on I saw how the four twisted rods of soft iron, which were now all melded into the harder steel, had been smoothed into wondrous patterns, repetitive curling patterns that made flat, smoky wisps in the blade. In some light you could not see the patterns, but in the dusk, or when, in winter, you breathed on the blade, they showed. Serpent breath, Brida called the patterns, and I decided to give the sword that name: SerpentBreath. Ealdwulf finished the blade by hammering grooves that ran down the center of each side. He said they helped stop the sword being trapped in an enemy’s flesh. “Blood channels,” he grunted. [...] And there is magic in SerpentBreath. Ealdwulf had his own spells that he would not tell me, the spells of the smith, and Brida took the blade into the woods for a whole night and never told me what she did with it, and those were the spells of a woman, and when we made the sacrifice of the pit slaughter, and killed a man, a horse, a ram, a bull, and a drake, I asked Ragnar to use SerpentBreath on the doomed man so that Odin would know she existed and would look well on her. Those are the spells of a pagan and a warrior. 
Has smoke-like curling patterns traced through its steel just as Beowulf's sword is said to have had.
A small silver cross - a gift from Abbess Hild Hildegyth - has been worked into the hilt.