Game of Thrones just gave us the biggest reveal yet... and you probably missed it.

Warning: This article contains spoilers for the latest season of Game of Thrones (and… pretty much every season before it). Read on at your own risk.

Tonight’s episode of Game of Thrones may have just been the most important yet.

Sure, there was pretty much the complete destruction of House Tarly (RIP Dickon), a secret meeting between Tyrion and Jaime (just how was he in and out of King’s Landing so quickly?), the return of a long-lost favourite character and and a pregnancy reveal.

So, yeah, a lot happened in an episode that three seasons ago would have been stretched into four separate episodes.

But, the most important moment was a sneeze-and-you-missed-it conversation between our beloved Sam Tarly and Gilly.

While sitting in his library, Gilly is practicing her reading and asks Sam to explain what an “annulment” is.

"Hey Sam, I think I just discovered something that alters the course of this entire show..." Image via HBO.

She explains she's just read about a High Septon performing a secret ceremony in Dorne for Prince Rhaegar (or "Ragger", as Gilly pronounces it), where he annulled his marriage with his lawful wife and married someone else.

Sam interrupts and rants about how crappy (at times, literally) his training has been before deciding to leave the Citadel but GUYS, DO YOU KNOW WHAT THIS MEANS?!

This changes everything. Image via HBO.

It means that Prince Rhaegar, Jon Snow's real father, was probably lawfully married to his mother, Lyanna Stark.

Seeing as he was legitimately conceived, within the bounds of marriage, it makes Jon Snow the rightful heir to the Iron Throne, and means he has a better claim to the throne than Daenerys Targaryen. Ouch.

"What do you mean 'no longer the rightful heir'?" Image via HBO.

It also explains why the Kingsguard were guarding Lyanna at the Tower of Joy, where Jon was born, and not Rhaegar's former wife and children - Rhaenys and Aegon, who were killed by Gregor Clegane during the Rebellion.

As Prince Rhaegar's legal wife, Lyanna was a little higher up on the 'priority protection list'.

We were reminded of Jon Snow's Targaryen blood in another scene in the episode, too, where he bravely strokes Daenerys' dragon Drogon.

Jon is now the only other person, besides Daenerys and Tyrion, to successfully touch one of the three dragons.

Three-headed dragon, anyone?

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