Fans had long guessed that the Game of Thrones R+L=J theory would eventually be confirmed. And in Sunday's season 7 finale, the revelation that Jon Snow's parents were Rhaegar Targaryen and Lyanna Stark (i.e. R+L) finally came.
It had been heavily foreshadowed in the show, but it was thanks to Bran Stark's Three-Eyed Raven powers that we got to hear about Jon's family tree. In his training, he had visited the the scene of Jon's birth and discovered his true parentage. But it was only when Samwell Tarly met Bran in the season 7 finale that viewers heard the actual words spoken. Bran told Sam that Jon was the son of Rhaegar and Lyanna, and asked him to inform Jon.
But even Bran didn't know everything in that moment—he told Sam that Jon's real last name was Sand, believing Jon was born out of wedlock in Dorne. But thanks to Gilly's discovery—that Rhaegar and Lyanna had actually been married in a secret ceremony, meaning Jon was a legitimate child from the Targaryen line—all the puzzle pieces came together. Bran then used his powers to "see" the wedding and confirm it.
It was an extremely satisfying reveal. The wedding scene was a poignant one; Bran notes that because the supposed kidnapping of Lyanna by Rhaegar prompted Robert Baratheon to wage war against the Targaryens, the relationship essentially spawned all the action we've seen in the Seven Kingdoms even since. Yet the war was based, essentially, on a lie.
Still, there was one small detail missing: Jon's real name. In the season 6 scene where Bran witnesses Lyanna giving birth to Jon, she tells her brother, a young Ned Stark, what the baby's name is. Internet sleuths had tried to deduce a little of what Lyanna said: "His name is [inaudible]. If Robert finds out, he'll kill him, you know he will," she said on her deathbed. "You have to protect him. Promise me, Ned." Some dedicated viewers even tried to lipread and research what the name might be, but came up short; others did land on the right name months ago.
And so, in "The Dragon and the Wolf," we hear Jon's name for the first time: Aegon Targaryen. "He's never been a bastard," Bran realizes. "He's the heir to the Iron Throne." But it's not just the last name and its royal heritage that is important. You might have heard the name Aegon before—because it's the name of Jon's older half-brother, who was killed by none other than Ser Gregor Clegane, or The Mountain, when the Lannisters attacked King's Landing. He was also often mentioned by Oberyn Martell, his uncle, as a reason for seeking revenge against The Mountain.
There have been plenty of Aegon Targaryens in the family line, including the first ever king from the Targaryen line (who was married to both of his sisters, apparently, so...Dany and Jon aren't looking so bad right now). The last Aegon Targaryen was Jon's great-grandfather, and he was the fifth of his name. That makes Jon Aegon Targaryen VI.
All in all, it's a huge reveal, and it sets up some fascinating questions for season 8. We saw Jon and Daenerys finally give in to their mutual attraction; although viewers know that they're related, they themselves have no idea as yet.