The Winds of Winter, the finale episode of Game of Thrones season 6 gave us the most important and long-overdue revelation that many fans were waiting for. Jon Snow, AKA the Targaryen baby of Lyanna Stark and Rhaegar Targaryen was given staunch confirmation in the episode, letting us know that the fan theory of R+L=J is actually true. Book fans have known this for ages, and the recent revelation on the show just gave it even more boost to talk about. If it wasn’t entirely obvious, we saw the baby’s face and then Jon’s face right after, which confirms the fact that he is Lyanna Stark’s son. Though the frustrating part is that the show didn’t let us know what Lyanna whispered into young Ned’s ear, we’ve got some equally determined fans who wouldn’t back down from finding out what it was. Hide all you want, show runners, we’ve found out what she whispered to her brother.

Reddit user sparkledavisjr who has apparently watched the Tower of Joy scene about fifty times, wrote this: “I’m not a great lip-reader, but I’m fairly certain what she says is Jaehaerys.”

Now, for non-book fans this might be an unfamiliar name, like many others. Jaeherysis the name of the fourth Targaryen king of the Seven Kingdoms, which was around 200 years before the series begins. Jaeherys I was dubbed ‘The Conciliator’ or ‘The Wise’, and about a century and a half after him was Jaeherys Targaryen II, the 16th king who ruled the Seven Kingdoms. He was succeeded by Aerys II Targaryen, more commonly known as the Mad King, and the father of Daenerys. The Redditor in question wrote a proper explanation of the fact that Lyanna whispered the name Jaeherys in Ned’s ear as following:

“If Lyanna was in love with Rhaegar (as seems likely), it makes sense for their son to have a Targaryen traditional name like his siblings Aegon and Rhaenys. Jaehaerys would be a good pick as the name isn’t associated with any real negative connotations, like Aerys, Maegor, etc. Not only is Jaehaerys the great-grandfather of Jon, he was the King who received the ORIGINAL PROPHECY about the prince who was promised from the woods witch with Jenny of Oldstones.”

“This prophecy is what caused Jaehaerys to force his children Aerys and Rhaella to marry, because it was prophesied that the [Prince That Was Promised] would be born of their line. Rhaegar was aware of this prophecy, and while he originally thought that he was the PTWP, he realized later he was not and that it would be one of his children. That is why he took/seduced Lyanna in the first place. His wife Elia could not have any more children, and he knew there must be a third child (The dragon must have three heads).”

Obviously Ned couldn’t have the boy designated as Jaeherys since that would clearly indicate that he was a Targaryen, based on the lineage and the kind of glaringly obvious Targaryen names are. Therefore, deriving ‘Jon’  from Jaeherys did seem to be acceptable, aside from the fact that he named the child after his friend Jon Arryn.