The following contains spoilers for George R. R. Martin's Fire & Blood and minor potential spoilers for House of the Dragon.

No matter what time period it is, in the Game of Thrones universe, dragons are majestic beings that drop jaws. To pet a dragon is a special privilege that not everyone is privy to, let alone riding one in the sky or in battle. The Targaryens and a few Velaryons have ridden dragons for centuries, but there are a group of individuals known as "dragonseeds" who have mounted the beasts. Dragonseeds are expected to be crucial players in the upcoming Dance of the Dragons in House of the Dragon Season 2.

As Rhaenyra Targaryen organizes her efforts to take the Iron Throne from Aegon II Targaryen, her oldest son looks to the underdogs for assistance. George R. R. Martin's Fire & Blood illustrates the contributions of the dragonseeds, some of whom stood by Rhaenyra until their dying breath, and others who took their newfound power for granted. It's always been pretty easy to understand why the Targaryens are the only dragonriders left in the world, but it can be a little more confusing to understand why these new people suddenly have the rarest gift of magic.

What Are Dragonseeds in Fire & Blood?

To understand the lore of the dragonseeds, one must also know the historical connections between House Targaryen and dragons. Before they migrated to Westeros, the Targaryens were just one of 40 great houses in Old Valyria known as "dragonlord families." There's not a solid theory on why these specific families were able to bond with magic, but it's likely because Valyrians used spells and magical dragon horns to tame dragons. The Targaryens were not even the most powerful in Old Valyria, but that all changed after the Doom of Valyria.

The Targaryens had moved to Dragonstone in Westeros years prior to the catastrophic event thanks to a prophetic dream, and were the only surviving dragonlord family. Their power was unmatched in Westeros, and brought the Seven Kingdoms together under Aegon I Targaryen's name. Unlike the Targaryens, dragonseeds aren't technically royalty, but they have royal blood. The Targaryens used to practice a custom known as the "first night," which is now largely extinct in Westeros. But at the time, the smallfolk of Westeros saw Targaryens as beautiful gods.

As part of the first night, the bride would sleep with the Lord of Dragonstone and give birth to his child, who was "born of dragonseed." The first suspected dragonseed in Westeros was Aegon the Conquerer's best friend, Orys Baratheon, but his relation to the Targaryen family was never confirmed. Although the tradition was outlawed by King Jaehaerys I Targaryen, it continued for many years and resulted in many alleged illegitimate Targaryen children living on or around Dragonstone. By extension, the children of dragonseeds may have also proclaimed themselves as such.

The Most Well-Known Dragonseeds in Fire & Blood

Dragonseeds were always an unspoken reality in Westeros. Fathering or birthing illegitimate children isn't a heinous crime in the country, but it disgraces a lord of their honor. Thus, the dragonseeds were never proclaimed as trueborn children of Targaryens. However, when Aegon II Targaryen usurped his older sister's throne after King Viserys I Targaryen's death, everything changed for the dragonseeds. Rhaenyra Targaryen's eldest son, Jacaerys, sought out new fighters for the Blacks. Rhaenyra's faction was greatly outnumbered in terms of dragons, as the Greens had the oldest and most war-experienced dragon in the world, Vhagar. But the Blacks sat on a gold mine in Dragonstone, where there were caves filled with wild dragons that hadn't seen light in years.

Jacaerys met proclaimed dragonseeds and offered them land, knighthood and money to anyone who could tame and ride a dragon. Many people who weren't dragonseeds tried and failed to master a dragon, resulting in their own deaths. In total, there were four successful riders: Nettles, Addam of Hull, Hugh Hammer and Ulf the White. Two other people were named as dragonseeds, but were unable to bond with a dragon: Alyn of Hull was Addam's younger brother and was determined to be a dragonseed by association. Silver Denys claimed to have the blood of Maegor I Targaryen's illegitimate son, but was attacked by Sheepstealer and killed by the Cannibal.

There was never any thorough investigation to confirm the dragonseeds' heritage. At the time, war was at the front of everyone's minds, so Rhaenyra took the riders she could get and blessed them with the dragonseed title. Their unconfirmed statuses didn't stop people from speculating about their relations. Addam and Alyn were legitimized as Laenor Velaryon's illegitimate children, although it was rumored they were actually Corlys' sons. Readers speculated that Nettles was actually Daemon Targaryen's daughter, which would've explained his unforeseen affection for her.

Are the Velaryons Dragonseeds in Fire & Blood?

Since Targaryens are the only declared dragonriders left in the world, the introduction of dragonseeds may lead fans to question the validity of the Velaryons' ability to ride dragons. The Velaryons were one of many Valyrian families that didn't ride dragons. As of the first season of House of the Dragon, the only Velaryon dragonriders have been Laena and Laenor Velaryon, and Rhaenyra's three eldest sons: Jacaerys, Lucerys and Joffrey. It's worth noting, however, that Rhaenyra's sons are only legally Velaryons; in reality, they're Ser Harwin Strong's children. Nonetheless, since they don't have the Targaryen's last name, does that make them dragonseeds?

The short answer is no, these Velaryons are not dragonseeds. They aren't illegitimate children and share one Targaryen parent (Laena and Laenor's mother is Rhaenys Targaryen). The sole prerequisite for being a dragonseeds is coming from Valyrian heritage, but not being a trueborn child. The true mystery, however, is the legitimacy of Addam and Alyn Velaryon. The book validates the brothers as Laenor's children, probably for the sake of sparing Corlys' honor in his wife's eyes. But Laenor is confirmed to be gay in the show, and has never been able to conceive children with women. The brothers have to be Corlys' children in the show, otherwise, House of the Dragon will run into a sticky plot hole.

House of the Dragon could easily solve the mystery of the brothers with the fact that the Velaryons have married into the Targaryen family for centuries. Chances are that a drop of Targaryen blood could be enough to bond with a dragon. No one even knows who Hugh Hammer and Ulf the White came from. Thus, it begs the question of whether a paternity test is the most pressing issue in a destructive civil war that burns down the Targaryen house for generations. For Rhaenyra Targaryen, a dragonseed's heritage is the least of her concerns when her own line is at risk of extinction.

House of the Dragon Season 2 premieres June 16, 2024 on HBO.