A Breath of Power - The Shining Orb, #1

The banished illegitimate son of the King wishes to see his father one more time. He will cross rivers, mountains, and borders in the hopes of being made heir to the throne. But a deadly plot by the King's brother, lords, and advisors may thwart that and plunge the whole kingdom, if not continent, into chaos. What he doesn't know yet is that the emergence of a new elvish group through a mysterious orb could threaten the entire world.