The Dark Citadel Omnibus

The Dark Citadel: When a dark wizard takes control of Balsalom and forces young queen Kallia into marriage, slave boy Darik bands with griffin riders and knights to defend their city.
The Free Kingdoms: The Dark Wizard marches against the Free Kingdoms while a wizard, warrior prince, and a freed slave boy mount a heroic defense. A young queen struggles behind enemy lines to keep her city free from the enemy's grasp.

The Golden Griffin: The dark wizard's dragons attack the griffin riders in their aeries. With her father dead, the young leader of the griffin riders must venture into the northern wilds to tame the powerful and elusive golden griffin. If she fails, her people will be scattered and destroyed.

The first three volumes of The Dark Citadel fantasy series by Wall Street Journal and USA Today bestselling author Michael Wallace.