Laenor Velaryon played a major role in episode three of House of the Dragon and that’s only a taste of his story. He’s played by Theo Nate in his teenage years and John MacMillan will take over the role in his later years, (similar to Rhaenyra and Alicent), which implies that his role will grow even bigger as time goes on.
Laenor is the son of two of the biggest names in Westeros: Princess Rhaenys Targaryen (Eve Best), and Lord Corlys Velaryon (Steven Toussaint). This makes him royal, wealthy, and because of his lineage, he’s a dragonrider. (More on his dragon Seasmoke later.) He has an older sister — Laena (Nova Fouellis-Mosé) — who Corlys and Rhaenys were trying to marry off to King Viserys in episode two, “The Rogue Prince.” Her young age made the match very uncomfortable and revealed how willing they are to have a Velaryon on the Iron Throne. Laena will be played by Nanna Blondell as an adult.
As the heir to Driftmark, Laenor stands firmly amongst the other great houses in Westeros and he’s close to the throne. His mother was passed over for the crown and her brother King Viserys (Paddy Considine) was chosen instead. Ever since, the Velaryons have been trying to attain more power to improve their station. Corlys says, “History doesn’t remember blood, it remembers names.” This makes Laenor a great bargaining chip with his high-ranking status, as he can be used to secure House Velaryon’s status in King’s Landing, and that’s been Corlys’ main objective.
A younger Laenor is seen in earlier episodes, but he doesn’t get much screentime until episode three, “Second of His Name.” Daemon (Matt Smith), Corlys, and their army have been fighting Crabfeeder and the Triarchy for three years without sign of victory. As Corlys talks about how they have to continue to attack, Laenor replies that it’s pointless sending the dragons because Crabfeeder’s created a chokepoint on the Stepstones and they keep retreating into their caves whenever Daemon and Laenor attack with their dragons.
It’s at this point where we see Laenor’s strategic mind. As Corlys’ brother Vaemond points out that Crabfeeder and his men have no reason to leave the caves, the young Velaryon offers an idea. He says that they need to offer him flesh to bait Crabfeeder and draw him out long enough to use their dragons. When he’s questioned about who would be bold enough to do it, Laenor answers that Daemon would be the perfect candidate. They move forward with the plan and Daemon arrives on the beach, drawing out the Triarchy for Laenor to launch a sneak attack with his dragon Seasmoke, blasting them with fire. Their forces arrive on the beach and decimate the Triarchy, including Crabfeeder.
This shows how impressive Laenor’s battle strategy is. While his elders were hitting their heads against the wall trying to find a way to defeat their enemies, it was Laenor who answered the call. The battle scene revealed how proficient he is on Seasmoke. The dragon is quite young and very fast, able to attack swiftly and with frightening precision. When Laenor is on dragonback, he’s highly excitable. As he was soaring and attacking the Triarchy, he was cheering like a kid in a candy store and gleefully yelled the famous, “Dracarys!”
In the world of A Song of Ice and Fire by George R. R. Martin, Laenor was born in 94 AC (After Conquest) and was given Seasmoke when he was about seven years old. The dragon’s pale with a silvery-grey color, which plays into his name along with his family house and its infamous seafaring legacy. As is customary with the other dragonriders in the series, he has a close connection with his dragon. House Velaryon comes from Old Valyria before the Doom and their bloodline is a source of pride and power in Westeros.