'House of the Dragon' Cast Breaks Down Their Roles in the 'Game of Thrones' Prequel (Exclusive)

Matt Smith, Paddy Considine, Olivia Cooke and more tease their roles in the Targaryen battle of succession.

Game of Thrones is back as the HBO franchise rewinds the clock hundreds of years in time to explore the political intrigue and personal dramas of the Targaryens on House of the Dragon, an all-new series adapted from George R.R. Martin’s Fire & Blood

Co-created and executive produced by Miguel Sapochnik and Ryan Condal and starring Matt Smith, Paddy Considine, Olivia Cooke and many others, the prequel finds the ruling house amid an intense battle of succession after the king fails to secure his line’s place on the throne with a male heir. But that is only the beginning of this saga. 

While speaking to ET, the ensemble cast, including Emma D’Arcy, Eve Best, Fabien Frankel, and Steve Toussaint, breaks down their many characters’ roles in the ensuing political chess match that plays out after members of the extended Targaryen family make a claim for the throne. 

Paddy Considine as King Viserys Targaryen


Chosen over Princess Rhaenys Targaryen (Eve Best) to succeed the Old King, Jaehaerys Targaryen, by the lords of Westeros, King Viserys Targaryen later finds himself in a similar predicament when he’s unable to produce a male heir and secure the line of succession. 

“Suddenly, when Rhaenyra’s mom dies while trying to produce an heir, she’s left without a mother. And Viserys is somebody that doesn’t know how to be a father to a teenage girl. So, that has kind of difficulties within itself,” Considine says, referring to Viserys’ daughter, Princess Rhaenyra Targaryen (Emma D’Arcy), whom he positions as the next in line. “And then also the fact of naming her heir and what that means to the realm, what a big decision that is and how that affects their relationship going forward is huge.” 

Despite issues surrounding who will succeed him -- either his daughter or his younger brother, Prince Daemon Targaryen (Smith) -- Viserys is considered a decent man who understands the role as the leader and caretaker of King's Landing. “He’s not a tyrant; he’s not corrupted by power or any of those things. He’s just a good man and a good king,” Considine says of Viserys, whose reign has coincided with a time of peace. “There’s no war in the kingdom.”

While there’s peace, this doesn’t necessarily make things easy for him, especially considering he’s not good at the political game that’s required to stay one step ahead of his most strident detractors. “In some respects, he’s not great at the political game,” Considine says, explaining that “part of being king is that you’ve got so many people pulling at you, so you’re being pulled in so many different directions and you cannot please everybody with your decision-making.”

He adds that Viserys is “somebody who’s trying to be a king who pleases everybody and ultimately that has a very detrimental effect on everybody later on.”

At the end of the day, “​​he thinks about if they would’ve named Rhaenys that he’d have been free of all this,” Considine says. “He wouldn’t have to do it because it’s a burden and it’s quite amusing that so many people are kind of vying for that power. They seem to think there’s a power that sitting on that throne possesses, but actually it’s a curse seat.”

Matt Smith as Prince Daemon Targaryen


Prince Daemon Targaryen is the younger brother to King Viserys and an heir to the throne. A peerless warrior unmatched by anyone else in King’s Landing, Daemon possesses the true blood of the dragon. But his fearlessness and ruthless nature on the battlefield (and as a dragonrider) is also what makes those in the realm nervous about how he would wield his power if he were to sit atop the throne. 

“They’re weirdly similar and weirdly opposite,” Smith says of the two brothers, noting that compared to Viserys, Daemon is “reactionary, impetuous and violent.” He adds that “there’s a madness to him.”

As for Daemon’s true intentions, whether that’s a desire to take over as king or not, is unclear at times. “I think his goals from day to day vary, depending on what side of the bed Daemon gets up on, to be honest,” Smith says. “He’s a bit like a Rottweiler. You never really know what you’re gonna get.”

He adds that “Daemon is interested in sort of conflict and chaos as much as he’s interested in power. I think he’s interested more in the obstruction of power than he is in actually attaining it. So, he goes about being as problematic as can be, and that sort of makes him feel interested and alive.” 

When it comes to the dynamic between Daemon and Rhaenyra, Smith says there is a “very close bond” between the uncle and niece. “There is something very unique about their relationship compared to anyone else. I think he treats her with more respect than he does everyone else,” he continues. 

(Watch Considine and Smith talk more about joining the series.)

Olivia Cooke as Alicent Hightower


Alicent Hightower is the daughter of Otto Hightower (Rhys Ifans), the Hand of the King, and is considered the most comely woman in the Seven Kingdoms. Raised in the Red Keep, she grew up as close friends with Princess Rhaenyra Targaryen. And during those years, Emily Carey brings Alicent to life onscreen.  

“We always describe Alicent as a product of the patriarchy. She is very acutely aware of where she fits into this world,” Carey says. “And I think when we find her, it’s not been an issue for her thus far. She’s quite content with where she is and she doesn’t mind where she’s going.”

But, of course, “things very rapidly changed due to decisions completely out of her control,” Carey says. Despite all the shifts in dynamics, the actress says it’s unclear how Alicent feels about it all. “She doesn’t know what she’s feeling. She doesn’t really know what to choose. But the key is that she’s made to believe she can choose when in reality she knows she can’t,” she continues. 

As a result of those decisions, when the series picks back up with an older version of Alicent played by Cooke, she’s grown close to the king and his innermost circle while her relationship with Rhaenyra has suffered.

“My version of the character is acutely aware of her role within the kingdom and how it’s one rule for her and then another rule for Rhaenyra,” Cooke explains. “And I think as someone who’s lived by the books all her life and has been impeccably behaved and been the poster child for a lady at court, I think [something] starts to fester in a really ugly way.”

Emma D’Arcy as Princess Rhaenyra Targaryen


When audiences first meet the king’s first-born child, she’s played by Milly Alcock. Despite being of pure Valyrian blood and a dragonrider, she was not born a man -- something that is both a gift and a curse as she finds herself thrust into the middle of a political battle she wanted nothing to do with. 

“There’s a lot of things going through her mind. You know, the most obvious one being the loss of her mother and how she’s never gonna have a mom again,” Alcock says of a young Rhaenyra, who “is put into a very difficult position because I don’t necessarily think Rhaenyra wants the throne.” 

Alcock notes that Rhaenyra “wants to use it as an agency to change the world around her” but not at the same expense as what her family has suffered. “She’s also aware that her father has put her mother in the position to keep trying to have heirs,” the actress says, noting that this is “one of those moments in your life where you question authority for the first time as a young person.”  

D’Arcy, meanwhile, takes over the role as an older version of Rhaenyra, who is at the center of an increasingly uncertain pledge to make her queen. “She’s a good person who is trying to figure out where she slots in, in terms of the Targaryen family and that great history, and how to live in the world authentically,” D’Arcy says. And despite her lineage, “she’s a person who also feels like an outsider in her family and an outsider at court. She feels to be at odds with how she’s read by the world.”

Despite being opposing choices for the throne, “her uncle Daemon and her are extremely alike. They sort of really see each other,” D’Arcy says. “There’s this deep recognition. And simultaneously, the rules apply completely differently to the two of them. And that’s purely as a result of their gender.”  

D’Arcy also adds that Rhaenyra is constantly questioning herself. “There’s something in the blood. Like, she has this old Targaryen fire and I think the question throughout the series is like, ‘When do you trust that? When do you let that burn in spite of the amount of chaos that a fire can cause?’” she explains, noting that Rhaenyra is conflicted over whether to do right by her father or choose a different path – and what that all looks like. 

The actress adds, “She’s at a fork in the road.” 

Meanwhile, when it comes to Rhaenyra’s relationship with Alicent, the dynamic between them certainly has shifted as they’ve gotten older and both of them have been positioned to fight for favor of the king. But, as D’Arcy points out, “it’s not the most fundamental desire,” she says. “The most fundamental desire, I think, is for some sort of reunification. But the circumstances make that kind of impossible.” 

(Watch D'Arcy and Cooke tease what's to come on the series.)

Steve Toussaint as Lord Corlys Velaryon


Known as “The Sea Snake,” Corlys Velaryon is the Lord of House Velaryon, a Valyrian bloodline as old as House Targaryen. His moniker comes from his time as the most famed nautical adventurer in Westeros history. “He did these nine legendary voyages in his youth and brought back wonderful things that he could turn into wealth,” Toussaint says, explaining that his self-made wealth is something “that’s a real source of pride but also it fuels his resentment.” 

Since then, he’s built his house into a powerful seat that is even richer than the Lannisters and that claims the largest navy in the world, making him a crucial asset to Viserys’ inner circle -- even if he’s still not happy that his wife, Princess Rhaenys Targaryen, was passed over as queen.    

“He doesn’t hide the fact that it irks him that his wife is not on the throne,” Toussaint says, noting that Rhaenys is a far more qualified ruler. “In fact, sometimes it looks as if it hurts him more than it hurts her because there are moments when he’s just like, ‘It should be you.’ And she’s like, ‘Ahh, leave it. We’re rich.’ And he’s like, ‘No, it should be you.’”

He adds that Corlys’ “motivation for an awful lot of this season is about the pursuit of his family’s legacy and planting their name in history.” 

As a result, the actor teases that Corlys is doing a lot of maneuvering “to get his wife or someone else in his family into a position of power.” And while that desire to elevate his family’s position is admirable, “he has this dangerous ambition” that could lead to more trouble than it’s worth. “His vision for the family -- where the family should be -- is what’s gonna cause a major rift” between him and his wife. 

Eve Best as Princess Rhaenys Targaryen


Princess Rhaenys Targaryen is a dragonrider and wife to Lord Corlys Velaryon. Commonly known as “The Queen Who Never Was,” Rhaenys was passed over as heir to the throne in favor of her cousin, Viserys. “She was the best candidate for the job at the time, but she was passed over because she was a woman,” Best says.

Consequently, “she doesn’t have a role as a result of this terrible miscarriage of justice,” Best adds, explaining that when Rhaenyra suddenly becomes the next in line to the throne it was like “a sword was plunged deep in her heart,” reopening a wound that she’s spent a long time trying to recover from. 

Best adds, “It’s very hard to switch off the voice in the head that says, ‘Why wasn’t that you?’” Since then, the actress explains, Rhaenys worked hard “for that not to turn bad, for that not to fester, for that wound not to turn rancid and to turn into something that’s bitter and vengeful.” But at the same time, “she’s human and so, those feelings inevitably are still there.” 

Moving forward, Rhaenys “has her choices to act as she does or to not act as she doesn’t,” Best teases. 

(Watch Best and Toussaint talk about the original series.)

Fabien Frankel as Ser Criston Cole


A Dornish descendant, Ser Criston Cole is the common-born son of the steward to the Lord of Blackhaven. While Criston has no claim to land or titles, he does have his honor and his preternatural skill with a sword.

When audiences first meet Criston, “it’s the first time he’s ever crossed over in this world,” Frankel says, explaining that “his life before this has been very solitary, fighting in the Dornish marches, growing up in Blackhaven.” 

And the commoner quickly makes an impression during a tournament in King’s Landing, which he “is very much an interesting welcome into this world,” the actor says, noting that he’s “so far removed from the world in which he grew up.” 

(Watch Frankel and Alcock discuss the Targaryen family.)

Graham McTavish as Ser Harrold Westerling


Ser Harrold Westerling has served in the Kingsguard since the days of King Jaehaerys. As a result, he is considered the perfect example of chivalry and honor within the kingdom. “He is immensely loyal,” McTavish says, explaining that “he has forsaken the things that most people take for granted: relationships, money, titles, land, all of that kind of stuff.” 

Instead, “he has devoted his entire life to this family,” the actor says, referring to the Targaryens. “It’s almost like a religious order, really. And he is this monk-like figure in some ways, a little bit like the Templar Knights.”

Within the Targaryen family, “he has a particularly strong relationship with Rhaenyra because he has known her since she was born,” McTavish says, noting the two “have a kind of father-daughter relationship to some degree” and that he’s “very pleased when he sees that she has been chosen to be heir to the throne.” 

(Watch McTavish dish on getting into character.)

House of the Dragon premieres Sunday, Aug. 21 at 9 p.m. ET/PT on HBO and HBO Max. 


Reporting by Stacy Lambe and Will Marfuggi