The HBO original series takes place nearly 200 years before Game of Thrones, delving into the days of the Targaryen rule and the events leading to its fall.
Paddy Considine - King Viserys I Targaryen
King Viserys Targaryen served as the central figure of House of the Dragon, as much of the Game of Thrones prequel revolved around the issue of succession and specifically who would inherit the Iron Throne after his passing.
The health of Paddy Considine's Viserys saw a gradual deterioration due to leprosy over the course of the season, from losing the skin off his face to entire limbs, the Westeros ruler's body slowly fell apart until his final death.
Prior to his death, Viserys appointed his only daughter from his first marriage, Rhaenyra Targaryen, as his heir. However, he was ultimately succeeded by Aegon II Targaryen, the first child of his marriage to Alicent Hightower.
While generally kind-hearted and a peaceful man, with a distinct hatred of conflict, Viserys certainly had his moments of rage across the debut season.
Milly Alcock - Princess Rhaenyra Targaryen
Milly Alcock was the first actress to play Rhaenyra Targaryen in House of the Dragon, playing the youthful princess prior to the huge 10-year time jump that came with the start of Season 1, Episode 6.
The bold young dragonrider was the only child of King Viserys' marriage to Aemma Arryn, and, despite her father's initial desire for a son, was appointed the first female heir to the Iron Throne.
Just ahead of the time skip, Rhaenyra was married to Laenor Velaryon, son of Lord Corlys Velaryon, by the arrangement of her king and father Viserys.
Emma D'Arcy - Queen Rhaenyra I Targaryen
From Episode 6 onwards, Rhaenyra Targaryen was played by Emma D'Arcy, with the heir to the Iron Throne now having three bastard children - Princes Jacaerys, Lucerys, and Joffrey - who were fathered by Ser Harwin Strong.
A conflict began to brew between Rhaenyra and her old friend Alicent Hightower, now technically her stepmother. The heir was certain Alicent wanted to disinherit her to place her Aegon, son of her and Viserys, on the throne instead.
It was at this time Rhaenyra continued to grow closer with her uncle Daemon, who she had a strong bond with since childhood, eventually leading to their marriage after forming a plan to take her current husband Laenor Velaryon out of the picture.
Although Rhaenyra Targaryen has not taken the Iron Throne, and she may never will, she has been referred to by the title of queen given how she contests the rule of her half-brother Aegon I Targaryen.
Matt Smith - Prince Daemon Targaryen
Matt Smith brought Prince Daemon Targaryen to life as a cruel, ruthless, and power-hungry renowned warrior. Although once heir to the Iron Throne, a fallout with his brother, King Viserys I, led to his replacement.
Daemon committed plenty of cruel acts throughout House of the Dragon, perhaps chief among them being his murder of his first wife, Rhea Royce, after which he went on to marry his own niece, Rhaenyra Targaryen.
The prince was not loyal in his marriage to Rhaenyra, however, the pair did have two children, Prince Aegon the Younger and Prince Viserys.
With a civil war with the rule of Westeros now underway, Smith's Daemon will continue to be a key player in Season 2 as a major participant in the conflict.
Emily Carey - Young Alicent Hightower
As one of House of the Dragon's younger characters, Alicent Hightower faces a recast after the Season 1 time jump, with Emily Carey - who also played the young Diana in 2017's Wonder Woman - being the first to tackle the role.
Daughter to King Viserys' Hand of the King, Otto Hightower, Alicent befriended Rhaenyra Targaryen from a young age. However, this relationship diminished greatly once Alicent, with pressure from her father, began spending more time with the king after his first wife's death, eventually leading to their marriage.
The couple had three children, Aegon, Aemond, and Helaena, but none were named heir to the Iron Throne, with Rhaenyra holding that honor. Although initially Alicent wasn't bothered by this, she became convinced Rhaenyra was plotting against her family, and, as such, conspired to have Aegon named as heir.
Olivia Cooke - Queen Alicent Hightower
After House of the Dragon's mid-way time jump, Olivia Cooke took over from Emily Carey as the older Alicent Hightower, now queen of Westeros through her marriage to King Viserys Targaryen.
Over the years, Alicent's influence at King's Landing only grew, especially as Viserys weakened. After the fallout between Rhaenyra and Alicent, the two didn't see each other for several years, with the two reuniting with cold resentment.
In a misunderstanding of Viserys' dying words, which were the Song of Ice and Fire prophecy, Alicent came to believe he was naming their son Aegon as his heir in place of Rhaenyra, spurring her endeavor to crown him king.
The conflict of Alicent and Aegon going against Rhaenyra for the Iron Throne will continue to be central to House of the Dragon in Season 2 as the Dance of the Dragon and a civil war gets underway.
Rhys Ifans - Ser Otto Hightower
Played by The Amazing Spider-Man's Rhys Ifans, Otto Hightower was renowned as one of the most wise and clever men in Westeros. This reputation grew so strong he was appointed Hand of the King to King Jaehaerys Targaryen, a role he held onto under the rule of King Viserys.
After Viserys lost his wife, Otto cought to advance House Hightower's place by setting him up with his daughter Alicent and calling for their first-born son Aegon to replace Rhaenyra as heir. This came despite his initial backing of her claim over the previous heir, Daemon, due to his hatred for the Rogue Prince.
Otto's mischievous nature and his spying on Rhaenyra eventually cost him his role as Hand, only to return years later after Alicent had his replacement killed. The Hightower's power in Westeros continued to grow as Viserys weakened until Otto was eventually able to have his grandson Aegon crowned King after his death.
Eve Best - Princess Rhaenys Targaryen
Wife to the Master of Ships, Lord Corlys Velaryon, Princess Rhaenys Targaryen is the cousin to King Viserys and the granddaughter of his predecessor on the Iron Throne, King Jaehaerys I Targaryen.
Eve Best's Rhaenys held the nickname of "The Queen Who Never Was" after a change in Jaehaerys' heir deprived her of her claim to the throne.
During House of the Dragon, Rhaenys and Corlys propose their young daughter Laena marry Viserys, however, the King instead opted for Alicent Hightower.
This led to a dispute between the families which was eventually resolved through the wedding of Rhaenyra and Laenor - the son of Rhaenys and Corlys.
Even through this apparent power grab, Rhaenys clearly still had compassion for her family, expressing concern at Viserys' declining health.
Steve Toussaint - Lord Corlys Velaryon
Lord Corlys Velaryon, the richest man in Westeros who serves as the Master of Ships on King Viserys' small council, earned the nickname of the Sea Snake for his adventuring past that reportedly may be explored in a future spin-off.
After King Viserys' passed up Corlys' proposition that he marry his daughter Laena, the Master of Ships departed King's Landing. It was through this matter he found common ground with Prince Daemon, and the two even waged a several-year war together, one which was eventually won.
Coryls did eventually come back to King's Landing after the arrangement was made for Rhaenyra and Laenor to be married, thus placing his future grandchildren in line for the Iron Throne after Rhaenyra's intended rule.
Fabien Frankel - Lord Commander Ser Criston Cole
After defeating Prince Daemon Targaryen in a duel, Ser Criston Cole won the favor of Princess Rhaenyra Targaryen, and effectively became her personal bodyguard as he joined the King's Guard.
The pair began a sexual relationship that only ended when Rhaenyra married Laenor Velaryon. This pushed Cole into a place of jealousy and depression where he even attempted suicide, only to be saved by Alicent Hightower.
This began Criston's new era of intense loyalty to Alicent, even supporting her son Aegon's claim to the Iron Throne, with him even being the one to personally crown the new King after Viserys' death.
Sonoya Mizuno - Mysaria
Mysaria debuted early in House of the Dragon as a pleasure house worker visited by Prince Daemon, who she developed something of a relationship with. But she eventually left him after losing interest in serving as a pawn to further his goals of taking the Iron Throne.
She later took on the name of the White Worm and formed a spy network, often working for the likes of Otto Hightower and even being instrumental in finding Prince Aegon so he could take the Iron Throne after Viserys' death.
Graham McTavish - Lord Commander Ser Harrold Westerling
Serving as the Lord Commander of the Kingsguard, Ser Harrold Westerling had an avid loyalty to the crown, King Viserys, and Princess Rhaenyra.
Even after the death of King Viserys when he was ordered by Otto Hightower to assassinate Rhaenyra at Dragonstone, Westerling resigned from his post in defiance of the order and the Hightowers' attempted power grab.
A Complete List of Cast and Characters from House of the Dragon
Along with the major players listed prior, many other actors and characters help shape the narrative of House of the Dragon throughout Season 1, with some expected to return for the upcoming Season 2:
- Matthew Needham as Lord Larys Strong
- Jefferson Hall as Lord Jason Lannister and Ser Tyland Lannister
- Harry Collet and Leo Hart play Prince Jacaerlys Velaryon
- Tom Glynn-Carney and Ty Tennant play King Aegon II Targaryen
- Ewan Mitchell and Leo Ashton play Prince Aemond Targaryen
- Bethany Antonia and Shani Smethurst play Lady Baela Targaryen
- Phoebe Campbell and Eva Ossei-Gerning play Lady Rhaena Targaryen
- Phia Saban and Evie Allen play Queen Helaena Targaryen
- Sian Brooke plays Queen Aemma Arryn
- Gavin Spokes plays Lord Lyonel Strong
- John Macmillan, Theo Nate and Matthew Carver play Ser Laenor Velaryon
- Bill Paterson plays Lord Lyman Beesbury
- David Horovitch plays Grand Maester Mellos
- Julian Lewis Jones plays Lord Boremund Baratheon
- Steffan Rhodri plays Lord Hobert Hightower
- Wil Johnson plays Ser Vaemond Velaryon
- Daniel Scott-Smith plays Craghas Drahar/ "The Crabfeeder"
- Ryan Corr plays Ser Harwin Strong
- Nanna Blondell, Savannah Steyn and Nova Fouellis-Mose play Lady Laena Velaryon
- Solly McLeod plays Ser Joffrey Lonmouth
- Rachel Redford plays Lady Rhea Royce
- Owen Oakeshott plays Ser Gerold Royce
- Elliot Grihault and Harvey Salder play Prince Lucerys Velaryon
- Arty Froushan plays Ser Qarl Correy
- Dean Nolan plays Prince Reggio Haratis
- Kurt Egyiawan plays Grand Maester Orwyle
- Paul Kennedy plays Lord Jasper Wylde/"Ironrod"
- Phil Daniels plays Maester Gerardys
- Luke Tittensor plays Ser Arryk Cargyll
- Elliott Tittensor plays Ser Erryk Cargyll
- Elliott Tittensor plays Ser Erryk Cargyll
- Paul Hickey plays Lord Allun Caswell
- Alexis Raben plays Talya
- Nicholas Jones plays Lord Bartimos Celtigar
- Max Wrottesley plays Ser Lorent Marbrand
- Roger Evans plays Lord Borros Baratheon
- Michael Carter as King Jaehaerys I Targaryen
- Garry Cooper as Lord Commander Ser Ryam Redwyne
- Anthony Flanagan as Ser Steffon Darklyn
House of the Dragon Season 1 is streaming now on HBO Max. Season 2 has yet to set an official release date but has been filming in the UK for several weeks now and is expected to wrap production between September and October 2023.