Before it was released in late November, George R.R. Martin's new book Fire & Blood teased that it would reveal the origins of Daenerys's Dragons. The book, which is a 300-year history of the Targaryens in Westeros, doesn't tell the story directly (since when does Martin do that!?) as much as it does hint at the mirky events that took place surrounding the last known dragon eggs.
We first saw these eggs early in Game of Thrones, when Daenerys's keeper Pentoshi Magister Illyrio Mopatis gave her three fossilized dragon eggs that came “from the Shadow Lands beyond Asshai. The eons have turned them to stone, yet still they burn bright with beauty.”
While they're not explicitly connected directly to Daenerys's eggs, Fire & Blood tells the story of Lady Elissa Farman, a noble woman close to Queen Rhaena Targaryen, who rode one of the last living dragons named Dreamfyre. As Fire & Blood explains, at some point Farman got bored with her life in Westeros and sailed off in secret to Braavos:
Lady Elissa had good reason for wanting more distance between her and the queen, however. A fortnight after her departure, Ser Merrell Bullock, still commander of the castle garrison, brought three terrified grooms and the keeper of the dragon yard into Rhaena’s presence. Three dragon eggs were missing, and days of searching had not turned them up. After questioning every man who had access to the dragons closely, Ser Merrell was convinced that Lady Elissa had made off with them.
When Rhaena found out that her dragons had been stolen, she took off to tell her brother King Jaehaerys, who dismissed the crime, saying, "Some spicemonger in Pentos will find himself possessed of three very costly stones." As the book explains, the eggs turn into stone when taken away from the Targaryen keepers.
Fire & Blood: 300 Years Before A Game of Thrones (A Targaryen History) (A Song of Ice and Fire)
Fire & Blood: 300 Years Before A Game of Thrones (A Targaryen History) (A Song of Ice and Fire)
Jaehaerys never made any effort to find the eggs, and instead kept an ear to the ground for any news of dragons being born. But the eggs were sold to a man who is described only as the Sealord of Braavos. And from there the trail goes cold until they, we should assume, end up in Illyrio's possession when he gives them to Daenerys hundreds of years later.
If this is true, then Daenerys's dragons—Drogon, Rhaegal, and Viserion—were descended from Dreamfyre, who is the only adult female dragon noted in the book to have laid eggs. She died during the Targaryen civil war known as the Dance of Dragons. But, it also remains possible that Daenerys's dragons are descended from the last dragon, who died 20 years later (and 150 years before the events of Game of Thrones) and left behind five eggs described as being hard as stone.
It's also worth noting that George R.R. Martin himself has pointed out that nothing in Fire & Blood—specifically the dragon rumors—are intended to be taken as fact. So like everything else in Game of Thrones, consider this all heavily researched fan theories than actual fact.
