House Targaryen is the most powerful house in Westeros and House of the Dragon. Known to have been the power to unite the Seven Kingdoms together during the Conquest, this house has, since then, been in power and ruled Westeros until their reign finally came to an end with Aerys II Targaryen after Robert's Rebellion.
In House of the Dragon, House Targaryen is the focal point, unlike in Game of Thrones, and some extremely interesting Targaryens have already made their mark on the show.
5 Jaehaeyrs Targaryen
King Jaehaeyrs was seen in the prologue for House of the Dragon when the Great Council was held to choose his successor. In the histories, he is remembered as one of the greatest Kings to ever live who ruled peacefully along with his wife Alyssa Targaryen.
He's known to have been the longest reigning Targaryen monarch and ruled Westeros for 54 years. As with nearly all Targaryens, Jaehaerys was also a dragon rider and he mounted Vermithor, Who was known to be the third-largest dragon after Balerion and Vhagar. Jaehaerys was extremely wise and, during his reign, the Seven Kingdoms will largely peaceful. He knew that House Targaryen could only be destroyed by itself, such was its power. As seen in the prologue, he ends up choosing Viserys Targaryen as his successor during the Great Council.
4 Viserys Targaryen
Viserys Targaryen is the current King of Westeros in House of the Dragon. As seen in the prologue, he was chosen as the next King by his predecessor, Jaehaeyrs Targaryen. Much of Viserys' reign is known to have been peaceful. However, the seeds for the Dance of the Dragons, as fans know, were sown during his time as king of the Seven Kingdoms. Viserys was not known to be a particularly strong man, however, he did all in his power to ensure that he lived up to his grandfather's standards.
Being a Targaryen, he was a dragon rider as well and is known to have been the last man to ride Belerion the Black Dread before it eventually died of old age. Interestingly enough, he never bonded with another dragon after. Eventually, he married Aemma Arryn and fathered Rhaenyra Targaryen. Aemma ended up dying in childbirth and their son, Baelon Targaryen died hours after. Viserys ended up naming Rhaenyra Targaryen as his heir, however, he remarried Alicent Hightower, and with her, had four children, thus, sowing the seeds for the Dance.
3 Rhaenys Targaryen
Princess Rhaenys Targaryen is quite an important character in House of the Dragon. Introduced at the very beginning in the prologue of the show during the Great Council, Rhaenys was one of the two potential successors to King Jaehaerys Targaryen. As fans know, Jaehaerys ended up choosing Viserys as his successor and, henceforth, Rhaenys came to be known as "The Queen Who Never Was."
She was the daughter of Aemon Targaryen and Jocelyn Baratheon and her claim to the throne was quite strong. Rhaenys is also a dragon rider and, her mount is Meleys, the Red Queen. She ends up marrying Lord Corlys Volaryon and together, the two hold tremendous power in Westeros.
2 Rhaenyra Targaryen
Rhaenyra Targaryen is the daughter of King Viserys and Aemma Arryn. She is the only living child of King Viserys from his first marriage. Rhaenyra was born with a taste for ruling and always wanted to impress her father and see her as more than just a little girl. After the death of her mother and the fact that Daemon mocked Baelon's death, Rhaenyra was named the heir by Viserys Targaryen.
Every major lord of Westeros swore fealty to her and declared her as the heir. However, things started to change later on when the King remarried Alicent Hightower, and Aemon Targaryen was born. Rhaenyra Targaryen becomes a key figure in the war that breaks out in the future. Fighting for the throne, she is an incredibly powerful woman with her massive dragon, Syrax, always at her side. In the future, fans expect to see a lot from her as she fights for supremacy against Alicent and her children.
1 Daemon Targaryen
Daemon Targaryen, also known as the Rogue Prince, is one of the most important characters in House of the Dragon. He is the brother to King Viserys Targaryen and has always supported his claim, knowing that one day, he would be the one to take over after him. Daemon is known to have had a thirst for power and, given that he is the finest warrior of his time, this is no surprise.
He's known to be a rather cruel man with a morally grey character. This was evident from how he ran the City Watch when made its Commander. Daemon is an incredibly powerful man and his dragon, Caraxes the Blood Wyrm, is known to be just as fearsome as him. Daemon also wields a Valyrian Steel sword, called Dark Sister. As the series moves forward, he will play an incredibly important role as the most dangerous man in Westeros.