The Hawk's Bride — Rebecca L. Gillan

Banished as a child, Lucan Hawk has grown to be a bitter warlord with a bad reputation. Now someone is killing the king's heirs. King Patton wants him named heir, assuming a shifter lord trained by black elves will be a harder target for an assassin. But Luc can't forgive his uncle for allowing the banishment ten years ago. Then he's offered a boon he can't refuse--the right to marry the only woman he ever loved! Caitriona, a human-born cat shifter, was orphaned as a young child and brought to Aintoch to be raised by the captain of the guard. Feisty and beautiful, Cait was Luc's childhood best friend and teen sweetheart. Though she knew she could never marry her elfin lover, she never forgot him. The night Luc comes for her, she thinks she's dreaming. But the dream turns to a nightmare when the assassin targets her!