So this is a bit of a tinfoil hat theory, and we may never really get an answer but GRRM tends to write parallel stories with many of the details the same and only a few key points different. For instance, Alicent and Ned are both offended that the ultimate heirs of the throne are bastards and consider themselves honorable, even puritan with regard to their morals. The difference between them (at least in the books) is that Alicent (and Otto) desperately want their blood on the throne, where Ned does not care for Sansa and his blood to be part of the throne's regime.

Character Crimes and Allegations

Inheritance Disputes in Westeros

• Historical Context: A notable case of questioning the line of inheritance in Westeros occurs between the Dance of the Dragons and the War of the Five Kings.
  • Example: Nerys and Aemon → Daeron.
• Blackfyre Rebellions: The Blackfyre Rebellions were fueled by several major tensions within the kingdom, including:
  • Integration of Dorne into the kingdom
  • Years of venality within the court
  • Separate power structures within the Seven Kingdoms

Writing Style of Fire and Blood

The narrative style in Fire and Blood presents events as disputed history, so the exact truth is often unclear.

Tinfoil Hat Theory: Parallels in GRRM’s Writing

George R.R. Martin (GRRM) often writes parallel stories with similar details but key differences. For instance:

• Alicent vs. Ned Stark: Both Alicent Hightower and Ned Stark are offended by the idea of illegitimate children ascending the throne and consider themselves highly moral. However, their motivations differ:
  • Alicent (and Otto): They are determined to see their bloodline on the throne.
  • Ned Stark: Ned does not care about his bloodline, such as Sansa, being part of the regime.

Speculation on Daeron II’s Parentage

I believe that Nerys and Aemon are the true parents of Daeron II. Here's why:

1. Aegon’s Accusation: Aegon later accused Daeron of being a bastard but did not disinherit him. The evidence is unknown, and we may never find out since GRRM needs to finish Winds of Winter before completing Fire and Blood 2.
2. Differences in Personality: Daeron’s personality was vastly different from Aegon’s, which is reminiscent of Sansa telling Ned Stark in A Game of Thrones that Joffrey was "nothing like that drunk old king." This isn’t enough to join the Blackfyre cause, but it raises suspicions.
3. Aegon’s Illegitimate Children: Aegon’s known illegitimate children, such as Aegor, Brynden, and Daemon, were all competent soldiers and military leaders.
4. Nerys and Aemon’s Relationship: There are quotes suggesting that Nerys and Aemon had feelings for each other. Aemon wept when Nerys was married to their brother, Aegon.
5. Affairs in the Red Keep: As seen with Jaime and Cersei, it’s possible for a Kingsguard and a queen to have an affair in the Red Keep.
6. Aegon’s Spite and Distaste: Unlike Alicent, who seeks power, the person questioning Daeron’s legitimacy gains nothing, making it less likely to be a power grab. It’s been said that Aegon questioned Daeron’s legitimacy out of spite, but this is an emotional interpretation given after the fact.
7. Gift of Blackfyre: Aegon’s decision to gift the sword Blackfyre to Daemon, an illegitimate son, suggests he had doubts about Daeron’s legitimacy. If there were no issues with Daeron, Aegon would have likely kept Blackfyre within the Red Keep. He also gifted swords to another illegitimate son, Brynden Rivers.

This theory, while speculative, is supported by circumstantial evidence and aligns with the complex motivations and parallel storytelling in GRRM's works.

Here’s a table summarizing the three legitimacy crises in Westeros: