M. K. Hume 
The Storm Lord: Twilight of the Celts Book II 
An adventure thriller of the fight for freedom

The legend of King Arthur lives on…

Crippled with hunger and weary to the point of collapse, Gareth Minor enters the fortress of Arden to deliver the dire news that Lord Arthur, the Last Dragon, has been captured by barbarians and taken to the frozen north. With Father Lorcan and Germanus by his side, Gareth embarks on a quest to rescue his master.

Meanwhile, in the Land of the Denes, Arthur and his fellow prisoners enrage the Dene King when they are presented at court. Fleeing for their lives, Stormbringer, their captor turned protector, leads them to safety. But the northern shores are under threat of invasion and Stormbringer and Arthur unite in battle, knowing few will survive…