Dragon Jousters is a four-book series byMercedes Lackey that could be described as "Ancient Egypt with Dragons".
The countries Tia and Alta (Fantasy Counterpart Cultures for Upper and Lower Egypt, respectively) have been at war for centuries. The elite soldiers on both sides are the Jousters; men who ride trained dragons into battle.
(Joust) follows the story of a young boy named Vetch. He is a Altan, and a serf: someone lower than a slave who is tied to the land they work on under their master. His Tian master, Khefti the Fat, is quite cruel, and Vetch is the last member of his family on the land, taking all of Khefti's beatings. Vetch's luck changes when Ari, one of the Tian Dragon Jousters, appears one day and takes him to be dragon-boy for Kashet, the dragon Ari raised since hatching (and thus unique in the jousters' ranks).
Life in the dragon jousters' compound proves to be much more pleasant that slaving away in the fields, but Vetch's relationship with all the dragon jousters is tolerating at best, (though he likes the dragons,) as he sees them as a symbol of the Tian power that killed his father and put the rest of his family into serfdom. The one exception to this Ari, whom Vetch respects and even grows to liking.
Vetch eventually gets his hands on a dragon egg of his own, which he raises to hatching in secret, calling the female Avatre. The novel culminates with he and Avatre escaping the compound by air, only to be caught by Ari and Kashet. Ari, though, has also grown to liking Vetch, and convinces the other Tian dragon jousters that Vetch died in the chase, then helps Vetch get to a nomadic people, known as the Bedu, who will help him complete his escape to Alta. It is revealed that, in the Atlan tradition, "Vetch" actually has two names, one for use during his childhood and one for adulthood, his "real" name. As the novel closes, he takes on his real name, Kiron, and flies on Avatre toward Alta.
The second novel (Alta) begins as Kiron and Avatre transition from the nomad lands into Alta. Not far inside the Altan border, the two of them save a girl from one of the dangerous "water horses" (presumably a hippo). The girl is Aket-ten, daughter of Altan noble Lord Ya-tiren; she has magic abilities, including the ability to speak telepathically to animals.
Lord Ya-tiren and the rest of Aket-ten's family take Kiron in temporarily to help him adjust to life in the City of Alta, central hub of Alta, a large city built on seven earthen rings separated by canals. Kiron and Avatre are accepted into the ranks of the Altan dragon jousters, and Kiron gets to start his own wing of jousters who are to raise their dragons from hatching, a new concept for the jousters. His wing of eight other boys includes Aket-ten's brother and one of the heirs to the Altan throne.
Kiron's group of friends (his wing, Aket-ten, and others) eventually surmise (correctly) that the powerful Altan Magi are exercising more and more control over the country, to the detriment of its citizens. Aket-ten is one of the first people targeted, due to her magic abilities, and later the heir in Kiron's wing is murdered when he tries to speak up leading to Aket-ten joining the wing. As the first step in an unsure plan to remove the Magi from power, the group decides they must leave Alta and remove the jousters from both armies...
The third novel (Sanctuary) follows the inhabitants of Sanctuary as they try to make their city as functional as possible, having to deal with battling the harsh elements of the desert, growing the ranks of the New Dragon Jousters, and sustaining the city as refugees from both Alta and Tia constantly trickle in.
Much of the novel follows Kiron as he tries to find his place the societal structure of Sanctuary, and his relationship with Aket-ten (and her family)...
The final novel (Aerie) follows the inhabitants of the combined Altan and Tian nation. After moving to the newly found city, re-named Aerie, the Jousters of the new country must find a purpose. At first that purpose is the securing of trade routes through the desert. That changes when out on patrol Kiron found a dead body coming in out of the desert...