While we know for sure that Jon’s real parents are Rhaegar Targaryn and Lyanna Stark, his name is something that’s confusing some people.
Bran revealed in the season seven finale that Jon’s real name is Aegon Targaryen – named after Aegon the Conqueror and many other Targaryen kings – however, fans of the books know that Rhaegar already had a son name Aegon.
Before he got together with Lyanna, Rhaegar had two children with Elia Martell, who were murdered by The Mountain when Robert Baratheon came to kill Rhaegar for taking his future wife away from him.
This fact was also confirmed on the show in season three when Prince Aegon and Princess Rhaenys are mentioned, so did the showrunners simply forget this fact when they chose Aegon for Jon?
There are a few theories as to why this might have happened. One is that Lyanna chose the name on her deathbed and assumed Rhaegar would like it given its history. However, she would have known of the other Aegon so it still doesn’t make much sense that she’d give her son the same name as his half-brother.
The other theory is that Rhaegar chose the name because of The Prince That Was Promised prophecy, however, it does feel like a bit of a stretch and that the showrunners simply forgot about the first Aegon Targaryen.
What would have made sense, was if Jon was named Aemon Targaryen, like his great-great-uncle, their connection makes the name more fitting.
Maester Aemon had a huge impact on Jon’s life and was like a father to him at Castle Black. There are some similarities between the pair as well as they were both considered the rightful heir to the Iron Throne, but ended up in the Night’s Watch.
Aemon was also close to Rhaegar with the pair known for exchanging letters, so it would have made sense from that angle as well.
Another Aemon also lived a similar life to Jon. Aemon the Dragonknight was the noblest knight and one of the finest swordsmen in the Seven Kingdoms. He was also the younger brother of another Aegon and pledged his life to the Kingsguard and carried a Valyrian steel sword.
It does sound like a more fitting name?