Editor's Note: The following contains spoilers for House of the Dragon Season 1 and the book Fire & Blood.Targaryens have always had strange customs, especially when it comes to marriages. They marry siblings and have, on occasion, taken more than one wife. The tradition is from Old Valyria, where the Targaryens are from, likely meant to keep their dragonrider blood pure. It is common among Targaryens, while the rest of Westeros finds it unthinkable (look at the reaction to Jaime and Cersei Lannister). Their practice of marrying brothers and sisters is well documented in their family tree. One example from House of the Dragon is Aegon II (Tom Glynn-Carney) and his sister Helaena (Phia Saban).
While they will marry outside the family, when necessary, it isn't the norm for them. The Targaryens are so used to this that when a generation has an uneven ratio of sons and daughters, the family gets even more messed up. The Targaryens in House of the Dragon have more than their fair share of family drama, but there is always room for more. Aegon II shows little interest in his sister/wife, unlike his brother Aemond (Ewan Mitchell). This raises the question of who may have fathered Helaena's children. Especially given the Targaryen history of sibling marriages, drama, and bastards, what might seem like a wacky theory might not be something to dismiss off-hand.
Targaryen Family Love Triangles Are More Common Than You Think
Although we haven't seen it play on screen, in George R. R. Martin's books, we've seen more than a couple examples of Targaryen family marrying and then subsequently getting into love triangles with their other Targ family members. Aegon the Conqueror had two sisters. It was tradition for him to marry Visenya, the older of the two. However, Aegon wed Rhaenys out of love, at least, according to the stories. The three siblings conquered Westeros together with the help of their dragons. But they didn't exist without conflict. Aegon had sons with both his sisters, which eventually led to a succession conflict – a problem that wouldn't have happened if one of his sister-wives gave birth to a daughter. Afterward, the Targaryen kings adopted the Westerosi customs of having only one wife at a time. But that doesn't mean Aegon I was in a unique situation by loving the sibling he wasn't obligated to marry.
Only a few generations after House of the Dragon, Aegon IV and his brother Aemon the Dragonknight had only one sister, Naerys. As heir to the throne, Aegon married her, but she and Aemon had a better relationship. Naerys and Aemon were said to be in love, especially after Aemon fought with Aegon at the wedding and later cried. Shortly after his brother and sister married, Aemon joined the Kingsguard, allowing him to spend time around his sister, meanwhile, Aegon and Naerys had an unhappy marriage. Aegon's numerous mistresses serve as one indication of this, and then he also stated that he loved nine women in his life, not including his wife in that number. After the birth of Naerys' son Daeron, rumors spread about who may be the true father, Aegon or Aemon. Aemon defended the queen in a trial by combat for the treasonous accusation and won. But the suspicions didn't go away. When Aemon died, Aegon IV himself publicly questioned the legitimacy of Daeron, but Daenerys, Daeron's sister, being Aegon's daughter, was never doubted.
Aegon IV and his siblings weren't the only ones to develop a love triangle. Aegon IV, as stated before with his many mistresses, would go on to father many bastards, including Brynden Rivers, Shiera Seastar, and Aegor Rivers. Shiera Seastar was the daughter of Aegon IV's mistress, Serenei of Lys, and she was widely considered the most beautiful woman in the Seven Kingdoms. Despite her beauty and recognized status as the king's daughter, Shiera never married. Supposedly this is because she didn't want to. However, she was known to have many lovers, including two of her half-brothers, Brynden and Aegor Rivers. The two always had a rivalry which only worsened when Shiera chose Brynden over Aegor. Brynden, better known as Bloodraven, wanted to marry Shiera, but she refused him. She did like the jealousy he expressed over her, perhaps making the situation worse.
So What's Happening With Aegon II, Helaena, and Aemond?
House of the Dragon fans have speculated that Alicent's (Olivia Cooke) children are in a similar situation, with Aemond being the true father of Helaena's children rather than her husband, Aegon. Targaryens have a history (or, in this case, a future) of sibling love triangles, so it isn't so outlandish to think Aegon II, Helaena, and Aemond might be in a similar situation. As was the case for Naerys and Aemon, Helaena and Aemond appear to be closer than she is to Aegon II. In Episode 7, "Driftmark," young Aegon (Ty Tennant) complained to Aemond (Leo Ashton) about his betrothal to Helaena (Evie Allen), to which Aemond replied that he would do his duty "if only mother had betrothed [them]." Aemond doesn't share Aegon's feelings about their sister, and his feelings toward her could have developed into more. Aegon shows disinterest in his family, preferring to rape maids and sneak into Flea Bottom for all sorts of debauchery. Helaena admits that she and Aegon don't have a healthy marriage (though she doesn't say it in those words). In her toast in Episode 8, "The Lord of the Tides," she says marriage is mostly being ignored by your husband "except sometimes when he's drunk." This statement implies that she and Aegon spend little time together, though it also shows the opportunity for Aemond to be the father of her children.
When Jacaerys Velaryon (Harry Collett) asks Helaena to dance, Aemond appears more bothered about it than Aegon, though it could be that Aemond has more distaste for his nephews. This is only one example of the relationship Aemond and Helaena seem to share. When Rhaenys (Eve Best) threatens the family on dragonback, Aemond protects Helaena. The two certainly have a good relationship, but that doesn't mean they have children together. After all, these things could be explained by the fact that they are siblings.
Perhaps the clearest and most tenuous "proof" of the theory is in Episode 9, "The Green Council," when Alicent is looking for Aegon. She uses the word "father," and Helaena's baby says something that could have been "Aemond." However, the baby's speech isn't clear enough to determine what it said with clarity, and it could have just been babbling. Or the baby could have been paying attention to something else entirely. It isn't much for the theory to hang on. But it is possible. After all, he says that if Aegon's isn't found in Episode 9, he would be next in line for the throne. But the truth is, Jaehaerys, Aegon's son, would be next in line. Did Aemond mean to say his son would be next in line? With Aemond's opinion that he deserves Aegon's crown and Aegon's disinterest in his family, Aemond and Helaena could easily have developed a relationship in the missing years we didn't see on screen.
Then Are All the Next Generation Targaryen Children are Bastards?
If true, the situation would also be an interesting parallel to their half-sister, Rhaenyra (Emma D'Arcy), and Harwin Strong (Ryan Corr), who have three sons together. However, Rhaenyra tries to pass them off as the children of her husband, Leanor Velaryon (John Macmillan). One of Alicent's primary arguments against Rhaenyra on the throne is that her children are bastards. The point becomes ironic if she wants her children, whose only descendants are bastards, to rule instead. Of course, Aegon and Aemond look enough alike that no one could really tell either way in a time without DNA testing. It would also add to the great Westerosi tradition of passing bastards off as heirs to the throne: Cersei's children, Rhaenyra's children, and now potentially Helaena's children. Aemond fathering Helaena's children isn't, by any means, a proven theory, but anything is possible when it comes to Targaryen siblings.