Úlfur hét maður, sonur Bjálfa og Hallberu, dóttur Úlfs hins óarga.
There was a man called Ulf, the son of Bjalf and Hallbera, daughter of Ulf the fearless
Hún var systir Hallbjarnar hálftrölls í Hrafnistu, föður Ketils hængs.
She was the sister of Hallbjarni Half-troll in Hrafnista, father of Ketil Haeng.
Úlfur var maður svo mikill og sterkur, að eigi voru hans jafningjar,
Ulf was a man so large and strong, that none were his equal.
I don't know if I've convinced you, because I'm not sure myself whether this would be classed as alliteration. Could higher authorities advise?
Cheers
Jed