In "GOT" season 7 episode 7, "The Dragon and the Wolf", we saw the long-awaited Rhaegar and Lyanna's flashback. Shortly after having witnessed their secret wedding, Bran time-travels again to the Tower of Joy and we finally discover what Jon's real name is: Aegon Targaryen. The problem is, Rhaegar already named his first born son Aegon... Many fans believe this is a major writing flaw, but we can explain why Jon's true name is Aegon.

Rhaegar's first born son

Aegon was the son of Elia and Rhaegar, the boy who was killed alongside his sister Rhaenys and his mother Elia by The Mountain.

You probably remember what the Red Viper screamed at the Mountain during their duel; "You raped [Elia], you murdered her, you killed her children". Well, Aegon was one of her children. After giving birth to him, Elia was told that she couldn't carry any more children. It's very important to note, at this point, that Rhaegar believed that his first born son was The Prince That Was Promised. Our dear Rhaegar was quite obsessed with prophecies. Keep that in your mind!

Dany's vision

Let's get back to "GOT" season 2. In the weird House of the Undying Dany has a vision in which she sees Rhaegar and his wife Elia. Rhaegar says that Aegon is the best possible name for a king and Elia asks him if he's going to write a song for him.

Rhaegar answers that the baby is TPTWP, and "his is the song of Ice And Fire".

Here's why makes sense for Jon to be named Aegon

Rhaegar's first born son was killed before Jon-I-mean-Aegon was born, and we should remember that the Kings guards and Lyanna knew about Rhaegar's death at the Trident when Ned Stark arrived at the Tower of Joy.

Considering that Lyanna is likely to be the one who chose the baby's name, Aegon is a good pick and here's why:

  • Lyanna knew that his son was the legitimate heir to the throne of the Seven Kingdoms, and her husband thought that Aegon would be a great name for a king.
  • It's reasonable to think that Lyanna may have realized that Rhaegar and Elia's son couldn't be the prince of the prophecy since the poor infant was dead. But if you consider that her son was even a better candidate for the role of the Prince That Was Promised, it's understandable that Lyanna passed on the name her husband chose for the child destined to be the legendary prince.

You see?

It actually makes sense for the she-wolf to have named her son Aegon. It may still not be that elegant to have two of Rhaegar's sons named that way (our bet? Jon's name in George R.R. Martin's fantasy book series will be different from the one adopted in the show), but it makes a lot of sense.