Following the season six finale of "Game of Thrones," "The Winds of Winter," fan conversation has been rampant surrounding the question of who Jon Snow's parents really are.
The Tower of Joy flashback scene in the finale confirmed Jon Snow is the son of Lyanna Stark, but it didn't reveal who Snow's father really is.
For years, "Game of Thrones" viewers believed Jon Snow was the bastard son of Ned Stark, but we know now he's really Ned's nephew. Before and after "The Winds of Winter" aired, there were fans on Reddit who theorized Jon Snow's father is really Rhaegar Targaryen, which would give Jon Snow the most legitimate claim to the Iron Throne.
R (Rhaegar Targaryen) + L (Lyanna Stark) = J (Jon Snow, or possibly Jaehaerys Targaryen).
This theory was more than plausible, but it seemed impossible to confirm, until at least next season. However, thanks to a recent infographic published by HBO's "Game of Thrones" blog, it appears we can confirm Jon Snow's father is in fact Rhaegar Targaryen.
As you can see in this infographic, Jon Snow has two "parent" lines stemming from his picture, one leading to Lyanna Stark and the other leading to Rhaegar Targaryen.
Case closed, I guess.