Vermithor, House Of The Dragon's Unexpected Visitor From The Finale, Explained
Warning: Spoilers for "House of the Dragon" Season 1 Episode 10
The finale of "House of the Dragon" Season 1 is finally here, bringing with it the true beginning of the Targaryen civil war as The Dance of the Dragons. Prior to the episode's climax — which gave us our first glimpse of dragon versus dragon combat, and kills off yet another major character — Daemon Targaryen (Matt Smith) and the rest of the Blacks loyal to Queen Rhaenyra Targaryen (Emma D'Arcy) devised a strategy for their inevitable conflict with the Greens, a faction led by Dowager Queen Alicent Hightower (Olivia Cooke) and King Aegon II Targaryen (Tom Glynn-Carney).
During these battle preparations, much and more is made of the fact that the Blacks have a far greater number of dragons than the Greens: specifically, they currently own seven dragons to the Greens' four, provided that one of those four is the legendary dragon Vhagar. Considering the fact that author George R.R. Martin has compared the power of Westeros' dragons to that of nuclear weapons; these numbers make it clear that the Blacks currently have a major advantage (via Vulture).
On top of that, Daemon also asserts that there is a slew of unclaimed dragons which can still be claimed and bound to their cause, including the legendary Vermithor and Silverwing, who both reside on the Dragonmont. Later in the episode, we actually see Daemon singing in High Valyrian to Vermithor in a cave — though you may not have realized it at the time, since this immense bronze dragon is only identified through subtitles. Adding to the confusion is the fact that we aren't given information about how Vermithor first arrived on the Dragonmont, nor who his rider was before he landed there.
Vermithor was the dragon of King Jaehaerys the Conciliator
To understand the importance of Vermithor, nicknamed The Bronze Fury for his unmistakable bronze hide, you first have to recognize the fact that his first rider was none other than King Jaehaerys Targaryen I (Michael Carter) — who we first met back in Episode 1 during a flashback to the great council of 101 AC, wherein he named Viserys Targaryen I (Paddy Considine) as his heir.
Book readers will know that Vermithor hatched from an egg that was placed in Jaehaerys' cradle as an infant and that at some point before the year 48 AC, an adult Jaehaerys had claimed Vermithor for his own (via a Wiki of Ice and Fire). Vermithor stayed by King Jaehaerys' side until the King's death in 103 AC, at which point Vermithor fled to a cavern within the volcano known as the Dragonmont. Vermithor has since brooded there throughout the entire reign of King Viserys I, and when we meet him in "House of the Dragon" he's nearly 100 years old.
In the books, it's said that only Vhagar and Balerion the Black Dread (Aegon the Conqueror's dragon) were larger than Vermithor, making him the second largest dragon in all of "House of the Dragon" and an important weapon for the Blacks — should they successfully claim him for their side.
Vermithor has a strong connection to another riderless dragon named Silverwing
Despite the fact that we don't see any other dragons during Daemon's surprising confrontation with Vermithor, it's worth noting that he shares his home on the Dragonmont with another riderless dragon, Silverwing. Silverwing was originally the dragon of Queen Alysanne Targaryen, wife of King Jaehaerys Targaryen I, and since the deaths of Jaehaerys and Alysanne, the two have both resided on the Dragonmont together.
According to the "Fire and Blood" chapter "The Dying of the Dragons," it's said that Silverwing and Vermithor also mated following their riders' deaths –- and although their specific lineage is not confirmed within the books, this is significant due to Daemon's previous claim about having "a score of eggs incubating in the Dragonmont." Indeed, on top of the potential power that would be brought to the Blacks should they successfully claim the massive Vermithor, it's possible that Vermithor and Silverwing have provided them with another clutch of eggs to secure the future of their faction.
Although it's currently unclear what role Vermithor will play in the next season of "House of the Dragon," his unexpected appearance in the season finale makes it clear that he and his potential brood of eggs could become an important part of the story moving forward.