Warning: Spoilers ahead for Game of Thrones Season 7. If you haven't seen the latest finale, proceed with caution. This theory about Jon Snow's name will make Game of Thrones fans cry so hard, but that shouldn't happen from a bad surprise or unexpected spoiler.
As fans of HBO's Game of Thrones know — and have suspected for some time, prior to the Season 7 finale's confirmation — Jon Snow's real name is, in fact, Aegon Targaryen. That's significant enough on its own, but shouldn't preclude fans from understanding why Ned Stark might have chosen to call him Jon. According to Mashable, Reddit user duh_metrius pointed out that stoic Ned Stark named his sons for men who were important to him: Robb for childhood friend (and later king) Robert Baratheon, Bran for older brother Brandon, and Rickon for his own father. Jon is technically Ned's nephew, but was raised like one of his own children. So, who is Jon named after?
Most would guess, and correctly so, that Jon Snow was named for Jon Arryn, whose death by poisoning is the catalyst for the entire series. Jon Arryn was brother-in-law to Ned's wife Catelyn and Lord of the Vale; he fostered Ned and Robert when they were young, and also served as Robert's Hand of the King until his death.
Since Ned was sent away from a young age, Lord Arryn was like his father: He taught him to fight, hunt, and grow into the role of nobleman with honor. Jon Arryn was like a father to Ned. And Ned named the boy for whom he cared like one of his own — though he was not, and could never be — Jon. Right from the beginning, author George R. R. Martin was cluing fans in! Ned raised Jon and loved him like a son, as another Jon had done for Ned. It's OK if you're crying. Who wouldn't be?
Quick recap: Why did Ned have to raise Jon Snow as a Stark bastard in the first place? Well, Jon was previously thought to be a bastard son of Prince Rhaegar Targaryen and Lyanna Stark, but as fans saw during this season of Game of Thrones, that was not the case. In fact, Rhaegar and Lyanna were in love, his wedding to Princess Elia Martell was annulled, and the two were wed in secret. Lyanna died in childbirth during fiancé Robert Baratheon's Rebellion (the war "built on a lie," as Bran succinctly put it), though not before revealing her ultimate secret to Ned: His name is Aegon Targaryen.
Fans have suspected this for some time: It makes Jon Snow the trueborn Targaryen heir, and the rightful claimant to the Iron Throne. Not only that, but he may be the "Prince Who Was Promised," a Messianic figure that appears in most of the Game of Thrones religions. It would be sweet if he guessed at why Ned (supposedly) chose to call him Jon — a hint that the man who raised him like a son still viewed himself as a father figure to Jon, and would love him no matter what. Let's just hope that no one on the other side clues in Ned about his nephew and his Aunt Daenerys.