In George R.R. Martin's "A Song of Ice and Fire" (ASOIF) universe, Jon Snow's true parentage is kind of a big deal.

Though this theory is not new at all, it is becoming more and more popular as the TV show, adapted from Martin's books, does the same. The theory contains certain spoilers, so read with caution.

Martin first published "A Game of Thrones" in 1996 and from the outset he led his readers to believe there was something he was withholding about Jon's true parents. All the reader knows for certain is that Ned Stark returned from Robert Baratheon's rebellion with a child he said was a bastard he fathered during the war (hence the last name "Snow," an indicator of a base-born child by a Northerner).

However, the widely accepted theory is that Ned's account is a lie. A quick look at Jon Snow's Wiki of Ice and Fire page can give you a rundown of the years-old theory, but here it is in a nutshell.

Rhaegar Targaryen (son of "the Mad King") fathered Jon with Lyanna Stark (Ned's sister) and Ned claimed that child as his own bastard after the two died. Ned also never discussed Jon's mother with anyone, not even his wife Catelyn, but he is constantly reminded of a mysterious promise he made to Lyanna before she died. To add to the intruige, the only man alive who may know of Ned's promise is Howland Reed, a character who has yet to appear even in the book series.

Of course, there are many layers to this theory and it is a driving force in the ASOIF story. So why is it all of a sudden grabbing attention on the Internet? YouTube, of course, and BuzzFeed and the Huffington Post.

Alt Shift X posted a video explaining the theory of Jon Snow's true parentage July 12, 2014, then BuzzFeed and HuffPost brought the video to its legions of readers shortly after.

The theory has been driving fans crazy for years. For example, a quick search for "Jon Snow true parentage theories" brought up a thread on the TowerOfTheHand.com forum. The thread apparently began in 2009 and its participants discussed the possibility that Jon and Daenerys Targaryen (Rhaegar's sister) are bound to end up together.

For all the theories in play, one thing is clear: Martin wants his readers to discuss Jon's parentage and that is why Lyanna's memory haunts Ned in the first book and it is why Dany is found constantly thinking about her dead family members who once ruled the Seven Kingdoms.