The domestication of wyverns has a long and storied history. What follows is an abridged version of how wyverns came to be wild beasts to the domesticated animals of modern air cavalry.
Wyverns are domesticated for their ability to carry a human rider while in flight. The first people to domesticate wyverns were the sorcerers of the ancient Ranelv Dominion. Modern domesticated wyverns trace their ancestry from two distinct species of wyvern from opposite ends of the Arante continent. These are now referred to as the mountain and azure wyverns.
Mountain wyverns are about as heavy as a modern medium wyvern. They stand about three meters high at the hump and have a wingspan of some fourteen meters. They average some half tonne in weight. They have spades on the ends of their long tails to help steer through the air. They also have the ability to ignite the methane that they exhale to give the appearance that they breathe fire. This is used as a threat display. A common hunting tactic for mountain wyverns is to land on the backs of sauropods and to rake at their long necks with their claws.
A mountain wyvern descends upon its prey.
The azure wyverns look more like the modern surger breed. Indeed, surgers trace their ancestry more from the azures than the mountains. Azures are about as large as a modern light wyvern. Their snouts are long with conical teeth and they cannot create an electric arc in between their horns. Their wings have high aspect ratio to better facilitate soaring. Their tails have long barbs on the last third of their length that can conduct electricity in between them. The tails are used to electrically stun prey and enemies. One common hunting technique for azure wyverns is to dip the ends of the barbed tails into a river and stun any fish that they see swim by.
An azure wyvern wades through a river.
These two sub-species were bred together to create the modern domesticated wyvern. The mountain wyverns provided the spade on their tails, their size, and the ability to create bursts of fire from their nostrils. The azure wyverns provided the electrically conductive barbs on their tails, their great length, and the ability to project saliva over long distances. The ability to project saliva over long distances combined with the ability to ignite exhaled gas allows wyverns to ignite their saliva into a flaming projectile.
Ranelv sorcerers used their sorcery to tame the wild breasts just as modern sorcerers do today. Wyverns are extraordinarily difficult to tame without the use of sorcery. For the time that the Dominion was a political entity, wyverns were not ridden by temporal men. Saddles and reins for wyverns existed but they were not as complex as those today. Sorcerers steered wyverns with mental commands conducted through the aether. Tack necessary to steer wyverns through the air was not invented until the end of the feudal age.
Wyverns were initially used to carry sorcerers through the air for the purpose of messengers and scouts. Using wyverns in combat may seem to be the more obvious choice for their abilities but this was rarely done in the early days of their domestication. There were few wyverns available and it was deemed unsuitable to waste them in combat. Few of the sorcerers presiding over the Dominion were willing to risk their valuable wyverns or their own lives in combat. Combat wyverns were utilized in small skirmishes as opposed to large-scale battles. There is little that a dozen or so wyvern can do against a legion of soldiers. The armies of the time utilized archers in sufficient quantity to pose a threat to wyverns.
When the first aeronauts took to combat, they were utilized as skirmishers and harriers. Their natural pyrotechnic abilities were used to shoot enemies from above. This was deemed too wasteful of their energy. A more economic use of a wyvern weapons was to swoop low over the battlefield and to rake columns of soldiers with their stunning tails. This would soften the enemies for ground cavalry to make short work of them.
The Feudal Age:
A number of domesticated wyverns escaped into the wild when the Ranelv Dominion collapsed. These wyverns went feral and interbred with their wild ancestors. Mountain wyverns have been nearly out-bred and almost all of them possess the ability to spit fire. Azure wyverns populations still exist though they are few in number.
The remaining sorcerers were discriminated against and had to live in secret. They were able to teach sorcery to others and pass on their knowledge. This includes how to domesticate wyverns. A few domesticated populations were sustained in isolated populations.
These small populations experienced growth in the late feudal age when sorcerers and temporal men came to an understanding and decided to work together for the greater good of humanity. Tack was developed to allow any man with training to mount and steer a wyvern in the air. Wyverns were selectively bred to be more docile so that they would be more accepting of men without the sorcery to tame them.
Wyverns play a critical role in modern militaries. They allow aeronauts to drop ordnance on targets from above. Any military that can field wyverns and maintain air superiority has a significant advantage over an opponent.
Aside from military roles, wyverns are also used as mounts for aeronauts working in postal and messenger services. A wyvern can fly over a greater distance than any land animal can run. Modern nations such as Nargathand, Basola, and Arkendeum employ aeronauts in their respective postal services. Private couriers and trading companies also use wyverns in these roles.