You'll definitely want to skip this post if you didn't catch the Game of Thrones Season 7 finale, "The Dragon and the Wolf," because there are some major spoilers ahead.
On last night's episode, one of the biggest and longest-running fan theories was finally confirmed as canon: Jon Snow isn't a bastard, but the rightful heir to the Iron Throne.
All was revealed during a conversation between Bran Stark and Sam Tarly. Though Bran knew Rhaegar Targaryen and Lyanna Stark were the parents of Jon, the youngest living Stark sibling assumed the union was illegitimate.
That's when Sam offered up even more game-changing information: Rhaegar's previous marriage was annulled, which made his union with Lyanna lawful.
This is all important, because it's information that Gilly, Sam's partner, discovered in "Eastwatch," the fifth episode of Season 7.
Though she had a bit of trouble pronouncing Rhaegar's name, Gilly was right on the money and basically exposed what is arguably the single most important plot point in the history of the show.