Books in the Chronicles of the Necromancer series

The world of Martris Drayke, second son of King Bricen of Margolan, is shattered when his older half-brother, kill the king and seize the throne. Tris is the only surviving member of the royal family and in a land where spirits walk openly and influence the affairs of the living, he suspects he may be the mage heir to the power of his grandmother.