Alright, let’s rewind a few episodes. If you recall, in the season six finale of Game of Thrones, Bran Stark went back in time to the day at the Tower of Joy where Ned Stark was battling with a Targaryen Kingsguard in order to save his sister Lyanna’s life.
Up until this scene, it wasn’t certain how exactly his sister had died. But the show confirmed the theory that Lyanna died in childbirth, her final words being “Promise me, Ned” which was a plea to keep her newborn son’s identity a secret.
The baby would then grow up to be one of the most crucial characters in the series, a legendary figure: Jon Snow, King in the North. You know, the guy fighting to save the living from the Army of the Dead?
Jon has no clue who he really is, still thinking that he’s the bastard son of Ned Stark and an unknown southerner.
If he knew who his biological father was, Jon wouldn’t look at Daenerys, his biological aunt, romantically.
If Jon never learned about who he truly is, his status as a secret Targaryen would still be enough to make him a mythical hero in the war for Westeros.
On top of all this, if anyone else ever found out about Jon’s father, he would become even more of an important character in the series.
So at this point, Jon Snow is bound to serve not just as the King of the North but also as the King of the entire Seven Kingdoms.
In the fifth episode of the seventh season, Gilly asks Sam if he knows the definition of “annulment,” because she’s reading about it in one of the Citadel’s books.
She reads, “Maynard says here…that he issued an annulment for a Prince Rhaegar and remarried him to someone else at the same time in a secret ceremony in Dorne.”
Without her even realizing it, Gilly just casually dropped one of the single biggest bombs ever on Game of Thrones. So I’ll let you soak in all that information. This was a huge spoiler regarding Jon’s Targaryen parentage!