Credit: HBO

One of the biggest mysteries on Game of Thrones, dating all the way back to Season 1 is, Who is Jon Snow’s mother? We still aren’t any closer to learning who birthed the bastard now than we were when the series began, but with Vanity Fair recently revealing that A Song of Ice and Fire author George R. R. Marti gave showrunners David Benioff and Dan Weiss permission to adapt the books after declaring himself satisfied with their undisclosed theory about who Jon’s parents are, we can’t help but offer up our own guesses as to who it could be, based on the show and some details from the books.

Here are our three biggest theories.

Lyanna Stark... by Rhaegar Targaryen. Perhaps the most popular theory floating around presumes that Jon’s Stark blood comes not from Ned, but from Lyanna, Ned’s sister. We are told that Lyanna Stark was found dead in a bed of blood by Ned after being taken away to Dorne by Rhaegar Targaryen, Daenerys’ brother, during Robert’s Rebellion. Robert, who was in love with Lyanna, claimed that Rhaegar had raped her, and Robert famously killed him during a battle at the Trident.

The rape has never been confirmed, and there were rumors that Lyanna and Rhaegar were in love and actually having an affair (Rhaegar was married to Elia Martell, who was also slain during the rebellion). The theory is that Lyanna and Rhaegar had a child together, and Lyanna died during the birth. Ned found her and promised to raise the baby as his own, which accounts for Lyanna’s famous last words: “Promise me, Ned.”

One reason why this theory is so popular is because it absolves Ned of fathering a child out of wedlock, which seems wildly out of character the very honorable Stark patriarch. It also means Jon has Targaryen blood, which is a plus for people who want to see the bastard and Night's Watch member somehow wind up on the throne.

Wylla. Ned Stark once told Robert Baratheon that Jon’s mother was a serving girl named Wylla. This could have been a way for Ned to disguise the truth of Jon’s parentage, since Robert would likely have the boy killed if he knew him to be the spawn of Rhaegar and Lyanna. By having a commoner as the mother though, Ned was leaving politics out of it, as no one would bother to question a bastard with such an insignificant mother. Of course, Ned also could be telling the truth. Wylla being Jon’s mother wouldn’t be the most exciting reveal, but wouldn’t it be just like GRRM to troll us like that?

Some prostitute. Robert’s Rebellion was a tough war, Ned was away from home for a long time. In fact, he had gone off to war right after marrying Cat. Men at war often use prostitutes, and was Ned so different? He could have had a moment of weakness and bedded a prostitute, leaving Jon Snow in her womb. Then, after his honor returned to him, he couldn’t in good conscious leave his child to be raised in a brothel, so he decided to raise him as his own. It makes sense that he would keep it secret, because no kid would want to hear that his mother was a whore. The theory makes sense as long as you can believe that goody two-shoes Ned would actually visit a prostitute while he was married to Cat.

Who do you think is Jon Snow’s mother? Let us know in the comments!