Viking Boy by Tony Branman
Gunnar is the son of a Viking chieftain, living peacefully on his family steading with his mother, father and their people - until they are raided by Skuli and his Wolf Men, who raze his home to the ground and take his father's life. Gunnar swears an oath to avenge his father's death and save his mother from Skuli - but first he must run to save himself. Murderous raiders, hand to hand battles to the death, mythical flying wolves and a relentless sea journey to the Land of Fire and Ice...Unknown to Gunnar, his life has been foretold, and he finds he has a destiny greater than his own story.