- "While the dragonlords brought the world to heel, the slave markets of their former enemies never lacked for flesh."
- ―Jorah Mormont
Dragonlords were the rulers of the Valyrian Freehold that rode and controlled dragons. They played a large role in the Valyrians' defeat of the Ghiscari Empire to the east and the Rhoynar people to the north, vastly expanding the size and power of the Freehold.
In the books
In the A Song of Ice and Fire novels, "dragonlord" was a title reserved for members of the forty noble families that vied to actually rule the Valyrian Freehold. They were called dragonlords because they could ride and control dragons using whips, horns and sorcery. It had long been the custom of the dragonlords of Valyria to wed brother to sister to keep their bloodlines pure, and they were said to be strikingly (some say inhumanly) beautiful. Polygamy was known among the dragonlords, but it was less common than incest and was considered somewhat odd. The books and expanded materials do not make explicit whether all dragon riders are also dragonlords; the difference may be in land ownership or familial prestige.
Although organized by families, the dragonlords were not noble houses as seen in Westeros – they did not have heraldry or mottos, and were not institutionalized in quite the same way, as multiple freeholders from the same family could participate in government relatively equally.
Throughout the history of the Freehold, the number of dragonlords no doubt fluctuated depending on circumstances. During Valyria's wars against the Rhoynar over a thousand years ago, there were at least three hundred dragon riders, the number sent against the army of Prince Garin (who was soundly defeated). It is not clarified if every dragon rider in the Freehold was also a dragonlord.
The Targaryens were a minor dragonlord family, far from the most powerful, but are the only family that survived the Doom of Valyria with dragons. Thus members of House Targaryen are known as dragonlords in Westeros, even after the death of all the dragons.