The Blacks are a political faction that support the claim of Rhaenyra
The blacks, previously known as the party of the princess, were the faction of House Targaryen and their loyalists who supported the ascent of Rhaenyra Targaryen as Queen of the Seven Kingdoms during the Dance of the Dragons and the years that preceded it. They were opposed by the greens.
It was abundantly clear in the season finale that Daemon truly values Rhaenyra as the queen, and it doesn't appear to be for his own gain. All of his actions indicate that he looks to her as his leader even before she's taken power and has every intention to get her to her rightful throne.
On one side we have the 'Blacks', the supporters of Queen Rhaenyra I Targaryen (Emma D'Arcy) who was the chosen heir of her late father King Viserys I Targaryen (Paddy Considine).
Rhaenyra will have two marriages (and two lovers) in House of the Dragon, with six children (technically three by each husband, the suspicion that the first three are by another man is a source of much violence and discord in Westeros).
In "Fire & Blood," Rhaenyra's longest-lasting relationship is with her uncle, Prince Daemon Targaryen. In addition to the age gap and the incest, their relationship starts off on an especially controversial foot, with rumors that he either seduced her or taught her to seduce Ser Criston Cole, resulting in his exile.
But, while time may heal all wounds, 10 years certainly wasn't enough time for Alicent's wounds to heal over being lied to by Rhaenyra. We last saw her find out the truth in "We Light the Way" that Rhaenyra lost her virginity to Ser Criston Cole (Fabien Frankel).
Rhaenys declares her continued loyalty to Rhaenyra, the heir that Lord Corlys swore to twenty years prior. She makes it clear to Alicent in their earlier conversation that the word of House Driftmark is not so easily swayed.
The Two Betrayers is the historical reference given to Ulf White and Hugh Hammer, two dragonseeds who betrayed the blacks for the greens in the First Battle of Tumbleton and had Silverwing and Vermithor burn the market town of Tumbleton.
Although House Stark remained uninterested in royal politics and aloof from court affairs, they maintained their support for Queen Rhaenyra Targaryen and established a Pact of Ice and Fire with Jace, where they would unite their houses with the sons of Cregan and Jacaerys.
They have a lot of love for each other and Daemon does still support Rhaenyra despite his temper in this episode. He still bends the knee to Rhaenyra and calls her his queen, and he's the one who delivers the news to her at the end that Lucerys (Elliot Grihault) is dead.
While House Of The Dragon episode 4 showed Daemon was able to seduce Rhaenyra by kissing and undressing her, he couldn't fulfill the act due to impotence.
Back in her chambers, Rhaenyra's gaze lands on the handsome Ser Criston Cole (Fabien Frankel). After some initial reluctance by Criston, who has much more on the line as a lowborn member of the Kingsguard, Rhaenyra playfully seduces her long-standing crush and they have sex.
That's right, during the Oct. 2 episode of House of the Dragon, Rhaenyra (Emma D'Arcy) and Daemon (Matt Smith) stopped fighting their feelings for one another and finally got together. However, this was more than just an illicit liaison, as Rhaenyra and Daemon got married at the end of the episode.
Sunfyre devoured Rhaenyra in six bites, leaving only her left leg below the shin. Prince Aegon the Younger was forced to watch his mother die, and Elinda Massey allegedly gouged out her eyes in horror.
A war of succession began with the death of Aegon's grandfather, King Viserys I Targaryen, early in 129 AC. Though Aegon's mother, Rhaenyra Targaryen, had been named heir to the Iron Throne by Viserys, Aegon the Younger's half-uncle, Aegon the Elder, was crowned King Aegon II in King's Landing.
Rhaenyra and the queen get in a scuffle, where Alicent is trying to attack Rhaenyra but the princess is pushing the queen away by her arm and shoulder. The king yells for Alicent to stop, and even Otto Hightower tells his daughter to release the blade. She does, but not before slicing Rhaenyra's arm.
Rhaenyra Targaryen is killed by her half-brother Aegon II Targaryen when he cruelly feeds her to his dragon Sunfyre. Don't worry, Aegon II and the Greens don't win the war, though the Blacks ultimately triumph and put Rhaenyra's son Aegon the Younger on the throne. Then he pretty much ran the kingdom into the ground.
One tale has it that Daemon Targaryen paid Ser Qarl to kill Laenor in order to eliminate Rhaenyra's husband, the better for Daemon to replace him. And it is true that Rhaenyra and Daemon married not long afterwards. But one thing isn't in doubt: Laenor dies.
Rhaenyra Targaryen, the rightful heir to the Iron Throne, briefly considered bending the knee to her half-brother King Aegon II in the Season 1 finale of House of the Dragon, thus sparing the citizens of Westeros years of dragon fire and bloodshed.
And he also acquired a dragonrider lover, Nettles, while they were married. Also betraying her was Lord Corlys Velaryon, who supported the Blacks at first but when the tide turned he turned to the Greens. Who betrayed Rhaegar Targaryen?
— then Rhaenyra officially loses her virginity to Ser Criston Cole. After Daemon leaves Rhaenyra all horned up and alone, she sneaks back into the castle and lets Ser Criston see her in her page boy disguise.
In "King of the Narrow Sea", Rhaenyra seduced Ser Criston after she herself was denied by her uncle Daemon (Matt Smith). She and her paramour spent the night together, and she was warm towards Ser Criston afterward.
The story of the princess and her valiant knight did not end as a fairy tale, though. A sordid and controversial story began to spread that Rhaenyra lost her virginity to her uncle Daemon at age 16. No one knows if that is true. But Targaryens had long married within the family to keep their bloodlines pure.
According to the accounts of Septon Eustace, prior to her turning sixteen, Rhaenyra lost her virginity to her uncle, Prince Daemon, after he seduced her.