As Game of Thrones' seventh season begins its march to what will no doubt be a shocking conclusion, the fate of the Seven Kingdoms is being decided by the fire of dragons, the clash of swords, and perhaps even the blade of a Valyrian steel dagger. However, the balance of power in Westeros may well be ripped asunder by what's in an old book. In the medieval world of Westeros, more people know how to swing a sword than read a book, much less have access to the volumes of history about the Seven Kingdoms that have been recorded. Those that do have access and are able to read, such as the Maesters of the Citadel in Oldtown, possess a different and equally vital kind of power: knowledge.
Though she's a wildling who can't fight, Gilly (Hannah Murray) gained more power than most people in Westeros when Sam Tarly (John Bradley-West) taught her how to read. Sam traveled to Oldtown to become a Maester specifically so he could discover a way to defeat the White Walkers. Thanks to Gilly, Sam will now return to Winterfell possessing the truth about the parents and true heritage of Jon Snow (Kit Harington), which has the potential to completely upend what everyone has believed about who has the right to sit upon the Iron Throne.
One of the most important and pivotal characters in the saga of Game of Thrones is someone audiences have only heard a few mentions of but have never seen: Rhaegar Targaryen. Rhaegar's past deeds, and the long buried secrets of his marriage record discovered by Gilly in this week's episode "Eastwatch," will have a monumental impact on the future of the Seven Kingdoms and the two Queens, Cersei Lannister (Lena Headey) and Daenerys Targaryen (Emilia Clarke), currently at war over who has the right to sit upon the Iron Throne.
But first, a refresher on just who the mysterious Rhaegar Targaryen was and why he has now become more important than ever to the unfolding drama of Game of Thrones:
THE PRINCE OF DRAGONSTONE
Rhaegar Targaryen was the eldest son of the Mad King Aerys and Queen Rhaella Targeryen. Known as the Prince of Dragonstone, he was the older brother of Viserys and Daenerys Stormborn. Rhaegar was married to Elia Martell of Dorne, and together they had two children: Rhaenys and Aegon. This is Rhaegar's immediate family tree as recognized across Westeros, but as we'll soon learn, there is more to Rhaegar's past than meets the eye.
At the conclusion of Robert's Rebellion, the war which ended the Targaryen dynasty roughly two decades before the first season of Game of Thrones, Jaime Lannister slew the Mad King. Elia Martell and Rhaegar's two children were in King's Landing when Tywin Lannister's forces sacked the city; Gregor Clegane AKA The Mountain murdered Rhaenys and Aegon before raping and killing Elia. Meanwhile, a pregnant Queen Rhaella and Viserys were safely on Dragonstone. After Rhaella died giving birth to Daenerys, loyalists to the Targaryens then brought Viserys and the infant Daenerys across the Narrow Sea to Essos to live in exile lest they be killed by the new regime usurping the Iron Throne.
As for Rhaegar himself, he met Robert Baratheon in the decisive battle at the Trident. Robert bashed in Rhaegar's chest with his war hammer and killed him. With the heir to the Iron Throne slain, Robert Baratheon became King. And, because history is written by the victors, the version of events established by the triumphant Baratheons and Starks is the history that took hold across the Seven Kingdoms. However, the accepted story about what Rhaegar Targaryen did to spark Robert's Rebellion was manufactured to hide the truth, which is known to very few in Westeros who are still alive.