While George R.R. Martin’s book initially left certain plot points as rumors rather than facts, House of the Dragon’s casting has secretly confirmed a major twist for Rhaenyra Targaryen. HBO’s Game of Thrones prequel series, House of the Dragon, is based on the book Fire & Blood, Martin’s historical telling of House Targaryen’s family line in Westeros. The TV show specifically takes from the section on the Dance of the Dragons, the Targaryen civil war for the Iron Throne that occurred nearly 200 years before Game of Thrones.

House of the Dragon’s trailer reveals that the story will begin long before the civil war commences, with the marriage of Rhaenyra Targaryen (Emma D'Arcy) to Laenor Velaryon (John Macmillan) 15 years prior teased on screen. This political marriage will be one of the most important aspects of House of the Dragon’s civil war, as it was subject to plenty of rumors and scandals both before and during the Dance of the Dragons. Perhaps the most significant controversy for the marriage of Rhaenyra and Laenor was the subject of their three sons’ true parentage, with the books all but confirming that Jacaerys, Lucerys, and Joffrey Velaryon were actually fathered by Harwin Strong, Rhaenyra’s sworn shield and rumored lover.

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The true parentage of Rhaenyra’s three Velaryon sons was only documented as a rumor in the book, but House of the Dragon has secretly confirmed the twist that Harwin Strong truly did father her children. The biggest clues to this twist are House of the Dragon’s cast and other book changes revealed in the trailer. While Rhaenyra’s three eldest sons were always subject to rumor because they didn’t look like their father or mother, the circumstances of these physical differences are more noticeable in House of the Dragon. In Fire & Blood, House Velaryon is described as having the same pale Valyrian features as the Targaryens, with House of the Dragon changing this trait to make the Velaryons black. However, the actor who plays Laenor and Rhaenyra’s eldest son Jacaerys Velaryon in House of the Dragon, Harry Collett, is white with pale skin and brown hair – phenotypes that would be highly unlikely and more accurately reflect the actor who plays Harwin Strong, Ryan Corr.

House Velaryon in House of the Dragon

While it’s possible that Laenor and Rhaenyra miraculously had children with their least dominant genetic traits, this doesn’t seem likely, especially since this twist plays such an essential part in House of the Dragon’s Iron Throne story. The twist that Laenor didn’t father Rhaenyra’s children is also supported by the children cast to play Laenor’s sister, Laena, who married Rhaenyra’s uncle, Daemon Targaryen (Matt Smith). While Laena and Daemon both have the same physical traits as Laenor and Rhaenyra, respectively, their two daughters, Baela and Rhaena Targaryen, are portrayed by black actresses. Laenor being the biological father of Jacaerys, Lucerys, and Joffrey is hardly a stretch in terms of Game of Thrones’ fantastical story, but this controversy plays too impactful of a role in House of the Dragon to not be visual confirmation of this twist.

The notion that Fire & Blood’s stories are largely subject to rumor and interpretation is a great asset for House of the Dragon, as the series can take liberties with the narrative without being unfaithful to the source material – a major point of contention for Game of Thrones. With George R.R. Martin teasing that House of the Dragon has even improved upon some aspects of his book, the series seems to be giving far more nuance to the unsubstantiated rumors having been provided the opportunity to confirm events that happened behind closed doors. In this way, the true parentage of Rhaenyra and Laenor’s sons is likely just the first of many book rumors that House of the Dragon will confirm as the truth.

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