Karen Miller: The Innocent Mage [2007] paperback

Enter the kingdom of Lur, where to use magic unlawfully means death. The Doranen have ruled Lur with magic since arriving as refugees centuries ago. Theirs was a desperate flight to escape a powerful mage who started a bitter war in their homeland. To keep Lur safe, the native Olken inhabitants agreed to abandon their own magic. Magic is now forbidden them, and any who break this law are executed. Asher left his coastal village to make his fortune. Employed in the royal stables, he soon finds himself befriended by Prince Gar and given more money and power than he’d ever dreamed possible. But the Olken have a secret; a prophecy. The Innocent Mage will save Lur from destruction and members of The Circle have dedicated themselves to preserving Olken magic until this day arrives. Unbeknownst to Asher, he has been watched closely. As the Final Days approach, his life takes a new and unexpected turn …