Harry Turtledove 
Chernagor Pirates 

Four hundred years ago the kingdom of Avornis lost the Scepter of Mercy, long the property of its kings – and the key to its destiny. All attempts to retrieve it have failed horribly. But without it, how long can Avornis keep resisting powers greater than its own?While young King Lanius dreams of being more than a mere figurehead, his fellow sovereign, the usurper King Grus, is defending Avornis against the shadowy plots of the Banished One – the dark god cast from heaven who seeks now to dominate the mortal world.With the barbarous, nomadic Menteshe holding the Scepter of Mercy – and civil war raging among the Chernagor city-states in the north – Avornis finds itself threatened on two fronts and prevented from regaining the Scepter. But the longer the kings go without acting on their dream of retaking the Scepter of Mercy, the greater the chance the Banished One will triumph…