Valdemar: Mage Wars Series by Mercedes Lackey, Larry Dixon

It is an age when Valdemar is yet unfounded, its organization of Heralds yet unformed, and magic is still a wild and uncontrolled force. Skandranon Rashkae is perhaps the finest specimen of his race, with gleaming ebony feathers, majestic wingspan, keen magesight and sharp intelligence. Courageous, bold, and crafty, Skan is everything a gryphon should be... moreIt is an age when Valdemar is yet unfounded, its organization of Heralds yet unformed, and magic is still a wild and uncontrolled force. Skandranon Rashkae is perhaps the finest specimen of his race, with gleaming ebony feathers, majestic wingspan, keen magesight and sharp intelligence. Courageous, bold, and crafty, Skan is everything a gryphon should be. He is the fulfillment of everything that the Mage of Silence, the human sorcerer called Urtho, intended to achieve when he created these magical beings to be his champions, the defenders of his realm--a verdant plain long coveted by the evil mage Maar.Now Maar is once again advancing on Urtho's Keep, this time with a huge force spearheaded by magical constructs of his own--cruel birds of prey ready to perform any evil their creator may demand of them. And when one of Urtho's Seers wakes from a horrifying vision in which she sees a devastating magical weapon being placed in the hands of Maar's common soldiers, Skandrannon is sent to spy across enemy lines, cloaked in the protective of Urtho's powerful Spell of Silence. less

It has been ten years since the magical Cataclysm, which destroyed the twin strongholds of the world's two most powerful Mages, killing Urtho, creator of the gryphons, and sending his forces into exile. Now Urtho's peoples—human and non-human alike—live in a terraced city carved into the face of a gleaming white cliff on the edge of the Western Ocean... moreIt has been ten years since the magical Cataclysm, which destroyed the twin strongholds of the world's two most powerful Mages, killing Urtho, creator of the gryphons, and sending his forces into exile. Now Urtho's peoples—human and non-human alike—live in a terraced city carved into the face of a gleaming white cliff on the edge of the Western Ocean. Secure at least, until the fleet of the mysterious Black Kings appears in their harbor, bringing envoys who inform the residents of White Gryphon that their newfound home lies on the northern perimeter of lands claimed by this powerful kingdom. Desperate not to lose their hard won home, Skandranon, along with his longtime friend Amberdrake, agree to accompany the envoys back to the Court of the Black Kings, hoping to negotiate an alliance. When a high ranking noble who opposes this alliance is found murdered, Skandranon and Amberdrake realize that they are up against unknown enemies who will stop at nothing, even the use of diabolical Blood Magic, to destroy White Gryphon. less

A dozen years of peace have passed in the city of White Gryphon - providing well deserved and much needed security for the people who had lost their homes in the magical Cataclysm which killed the Mage Urtho, creator of the gryphons. But the inhabitants of White Gryphon have not forgotten their long struggles, and have trained an elite guard force, the Silver Gryphons, to protect their city, and if necessary, to join with the army of the Black Kings for mutual defense.