Game of Thrones fans were already very well aware that Jon Snow is the son of Rhaegar Targaryen and Lyanna Stark, but there's one mystery surrounding Jon's true identity that's been plaguing viewers for a while. But in Sunday night's Game of Thrones Season 7 finale, we finally got the answer — at long last, we know Jon Snow's real name. Spoiler alert: This post will discuss the details in the Game of Thrones Season 7 finale "The Dragon and the Wolf." After Bran and Sam learn about his true parentage, we also find out about the name Rhaegar and Lyanna gave him at birth: Aegon Targaryen. That's right; Jon doesn't just have the Targaryen surname, but also a traditional Targaryen first name to match.
As fans of the show have known since the very beginning (since every other reference to Jon Snow in Season 1 was "Ned Stark's bastard"), Jon Snow was never the character's real name. Snow is a surname given to bastards born in the North, and Jon believed he was Ned Stark's illegitimate son up until Sunday night's finale. Of course, viewers have known Jon was actually half Targaryen and half Stark for quite some time now. And at long last, Jon is finally, finally going to know it, too.
Ned likely gave his sister Lyanna's son the name Jon after Jon Arryn, a former Hand of the King who served as a father figure to Ned before the events of the series. Of course, Ned couldn't allow Jon to keep his given name of Aegon since it's clearly of Targaryen origin.
So now that Jon Snow officially is really Aegon Targaryen, is he going to drop the fake name he's been going by all his life? We'll have to wait until Season 8 to see if he makes everyone call him Aegon instead of Jon.