Viking Warrior: The Strongbow Saga 1
Synopsis (via goodreads):
He's the son of a chieftain and a princess—yet Halfdan was born a slave.
Now he is becoming a man and it is time for him to meet his destiny.
Though raised a slave who could only dream of freedom, young Halfdan's fate may be about to change. If freed, he may train as a Viking warrior, and come to know the glories of true brotherhood and the horrors of unspeakable evil. In the world of Vikings, a warrior's destiny is forged in the heat of battle. If the fates decree it, Hafdan may emerge as a new hero . . . a new myth . . . and perhaps a new legend.