And just like that, in the final minutes of the episode Rhaenyra the Cruel (2x02), Otto Hightower mentioned for the first time in  House of the Dragon Daeron, the fourth son of Alicent and Viserys, who had never been referenced on screen until now and whom many believed had been left out of the adaptation.

It was a moment of confirmation for readers, putting an end to speculation about whether this character had been removed from the plot or not, but also of confusion for viewers, who, not having read Fire and Blood (and are by no means obliged to do so), did not know who they were talking about and did not remember if they had seen him before or not.

The answer is no. Daeron did not even appear when Alicent and Rhaenyra's children were young.

Whichever way you look at it, there's an inevitable feeling that he was pulled out of thin air, but there are actually two reasons to justify his absence. One is practical. During childhood and in the moments narrated during the several years covered by the first season, Daeron plays no role in the plot, so they did not consider it necessary to add another name for the viewer to learn, who would then have to get used to the change of actor after the time jump in the following episode.

The other reason is narrative, as in Fire and Blood, Daeron is not in King's Landing, following a tradition that we will explain below.

Where has he been all this time

Daeron Targaryen has been at the Hightower House in Oldtown since at least before the birth of Rhaenyra's son, Joffrey Velaryon. When the timeline of season one jumped 10 years from Rhaenyra's wedding to the birth of her son Joffrey, the only children of Alicent and Viserys present in King's Landing were Aegon, Helaena, and Aemond.

Since the two eldest children of King Viserys I Targaryen already had roles in King's Landing, the third male, Daeron, is sent to Oldtown to be a squire and cupbearer to Lord Hobert Hightower, Otto's brother.

This was a common practice in medieval times, particularly among the nobility. Younger children who did not have a designated role in the palace were sent elsewhere to grow up away from the court and learn things.

He has a dragon

He has not appeared or been mentioned, but Daeron has had a dragon since he was six years old: Tessarion, and both will participate in the Dance of the Dragons, where he will be known as 'Daeron the Daring'. We won't give more details to avoid spoilers from the book and the series.

Tessarion is a female dragon, also known as the Blue Queen. As revealed in the book, Daeron is the only known rider of this dragon with blue wings and coppery scales. It is not clear which dragon laid the egg from which Tessarion hatched, although the egg was placed in infant Daeron's cradle.

Among the combat-capable dragons of the Green Team, Tessarion is the youngest and is described as only a third the size of Vermithor, which will be claimed by a 'dragonseed' bastard.

Who will play him in the series

In statements to Variety, the showrunner of the series, Ryan Condal, confirmed that the actor to play Daeron has not yet been chosen for the series, confirming that we will have to wait until the third season to see him (the series has already been renewed).

"Daeron has not been chosen yet. At this point in the story, he is in Oldtown, where he has been since he was young. So we don't have a perspective character in that world yet and there is no dramatic reason to go there."