Dragons are one of the most powerful creatures on Toril, possessed of enormous reserves of strength, intelligence, and magical prowess. Yet dragons are not a native race, they were created millennia ago and are thus one of the few magically created races that are able to breed true among their own kind.
Dragons have a long history on Toril, the scattered annals of the Aearee creator race claim credit for their conception as a slave race, however, the fossil record shows no creature resembling dragons from so long ago, indeed the first true dragons did not arise until well after the fall of the Aearee when they are noted in the history of the giants heralding the Thousand Year War between giant and dragon kind.
Draconic history tells that they were created by Bahamut and Tiamat from the blood of Asgoroth, and although Bahamut and Tiamat are recognize as having existed, their is no indication that they created dragons themselves.
The truth of the matter is somewhat confusing and still largely unknown, but sometime following the Tearfall, a new type of creature appeared upon Toril. This creature resembled the reptilian races that had long ago claimed the surface of Faerun and were now under threat from other creatures of air and water.
These feathered “dragons” were, voracious, and naturally semi intelligent. The Aearee saw the potential in their primitive cousins and selectively bred a creature capable of flight, large size, and taking instruction. Monstrologists name this creature the Eo-Draco, for it was not a dragon, it possessed none of the dragon’s magical capabilities, nor was it able to achieve the same size, strength, or intelligence of a dragon (and most tellingly the breath weapon was completely absent).
At some point during the history of the Aearee Empires (for there were at least 3), a being came to the Eo-Draco and bestowed gifts (golden scrolls) upon the greatest of its kind; Nagamat. These scrolls allowed the Eo-Draco to learn of magic that allowed them to rise up against their masters. The Eo-Draco were also aided by huge flying reptilian allies that possessed a number of curious inherent capabilities (including a breath weapon), and these allies when combined with heir newfound magic allowed the dragons to escape their servitude and bring ruin to the Aearee.
The Eo-Draco and their reptilian allies were cross fertile and the offspring known as Eo-Draconis were much larger, scaly, and possessed of strange capabilities (such as breath weapons or the ability to breathe underwater), but they were still not dragons for they were not inherently magical in themselves even though they could use magic (in the same way that a normal human can use magic but is not inherently magical unlike the sarrukh for instance).
The first true dragon came towards the end of the Thousand Years War and it is believed that here Bahamut and Tiamat can take credit for their “creation”. Through some unknown magic, the dragons permanently tied themselves and their progeny to the Weave, giving themselves inherent magical abilities that appeared with age rather than experience. From that day onward, the last of the Eo-Draconis died out in the final days of the Thousand Years War, and the surviving true dragons inherited Faerun.
Over time, particular subspecies of dragons have appeared and others have been created as detailed below.
Tiamat and Bahamut are not the only creatures to have tied themselves to the Weave, the sarrukh did so before the dragons, and elves have done so since. Nor are Tiamat and Bahamut the only dragons to have done so.
At some point during or following the Thousand Year War, a dragon known as Sardior (real name Auppensaradior) performed a similar although distinct ritual that cocooned him within a gigantic crystalline chrysalis, and he emerged as the first gem dragon.
Sardior performed a similar ritual upon true dragon eggs that he gathered and from these eggs he created the gem dragons of today.
Brown Dragons are curiously found almost exclusively in and around the Raurin region, leading many to believe they were created by the Imaskari who were known to use dragons as servants.
Brown Dragons were created in the Raurin region (although a few have since flown to other desert lands which is their preferred habitat), but not by the Imaskari. The true creator of the brown dragons is a Turami sorceress named Tlaa who fled to Raurin seeking allies against her enemies; the Mulan.
Tlaa would come to be known as TiaMa’at, the Queen of Chaos, Nemesis of the Gods, the Dark Lady, but in the Raurin Desert she was little more than a sorceress with a burning desire for vengeance against those who slaughtered her kin. In the growing Raurin Desert she found one of the fabled Imaskarcana, and from it learned the secrets of Transmutation.
With her newfound magical skills, Tlaa imbued herself with different forms, growing quite enamoured with the dragons that lived in this region (having escaped their bondage when the Imaskari Empire fell) she chose dragons as her primary form. It is believed she lay with many dragons and sired many children and experimented on them while within her. The product of these experiments was the Brown Dragon, a desert loving creature despised by almost all other dragon kind (who regard it as a bastard creation of a lesser being) but who willingly ally with the Cult of TiaMa’at and regard her as “mother”.