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When Samwell Tarley — as angry as we’ve ever seen him — finally let Jon in on the secret of his parentage, he didn’t simply stop there. Sam went on to insist that Jon’s true heritage made him the rightful king of the Seven Kingdoms. In the moment it’s easy to brush that assertion off as a (somewhat justified) backlash to Daenerys after learning that she had executed Sam’s father and brother. Yet, Sam essentially undermining Dany’s claim to the Iron Throne by naming Jon the rightful king wasn’t simply an outburst of emotion. By the established laws of Westeros Jon does in fact have the stronger claim.

The laws regarding succession to the Iron Throne weren’t established until over one hundred years after Aegon’s conquest of Westeros. As the long rule of King Jaehaerys (Aegon the conquerer’s grandson) was coming to a close, debate raged over who was first in line to take the Iron Throne when the old king was gone.

To establish the pattern of succession Jaehaerys called a Great Council in 101 A.C. — assembling all the lords of Westeros, maesters from the citadel, and septons/septas of the faith. All of Jaeherys’ children had perished or fled Westeros save two — his son Vaegon who had ascended to archmaester of the citadel and his daughter Rhaenys. However the claims of both were dismissed — Vaegon’s based on his prior vows as a maester and Rhaenys based on her gender.

As such the potential heirs to Jaehaerys were narrowed down to his grandson Viserys Targaryen (the son of his son Baelon) and his great grandson Laenor Valereon (the son of his grand-daughter Rhaenys Targaryen, who in turn was the daughter of his eldest son Aemon). While the matter was thoroughly debated, Viserys was deemed rightful heir by an overwhelming margin. The decision of the Great Council thus established an “Iron Precedent” that the throne could not pass to a woman, nor through a woman to her male descendants.

Consequently, Sam was speaking accurately when he claimed Jon was the rightful heir to the Iron Throne. By the (admittedly misogynistic) laws of succession, Jon has a stronger claim as the son of crown prince Rhaegar and grandson of the Mad King Aerys than Daenerys does as Aerys’ youngest daughter.

Targaryen Family Tree, Credit: Vox

Perhaps the more pressing question is how Jon decides to handle the revelation. Much has been made of the fact that Jon learning his true parentage would also mean Jon learning that his relationship with Daenerys was thus incestuous. Yet the consequences of that uncomfortable truth could pale in comparison to those related to the succession. Jon has already bent the knee to Daenerys — a decision that has received mixed reviews in the north, to put it gently. Despite his stronger claim, Jon may elect to stand by his vow and stand aside as Daenerys ascends to the throne.

However should Jon embrace his claim, as Sam seems to feel he should, then things could get very interesting. First and foremost, Jon’s claim to the Iron Throne depends on a truth that was kept secret from the entire realm. To our knowledge only Sam and Bran are aware of Jon’s true parentage. While Sam may have written evidence of Rhaegar annulling his marriage to Elia Martell, he doesn’t appear to have any documentation of Jon’s parentage. Bran has seen the truth in his visions, but it’s hard to believe the kingdom would just accept the word of a young man calling himself the “Three Eyed Raven” as truth. The only other individual who could vouch for Jon’s true parentage would be Howland Reed — the father of Meera and Jojen — who was there with Ned Stark at the Tower of Joy.

Even if Jon Snow’s claim is accepted as valid, it’s anyone’s guess how Daenerys would handle the news. Ever since her brother Viserys was crowned with molten gold by Khal Drogo, the Mother of Dragons has been convinced she held the best claim to the Iron Throne. While Jon’s claim may be stronger based on the decision of the Great Council, it seems doubtful that precedent established 200 years ago would deter Daenerys from pursuing her claim to the throne.

The consequences of dueling claims to the Iron Throne have historically ended in tragedy. Upon King Viserys’s death, the king’s eldest daughter Rhaenyra asserted herself rightful heir to the Iron Throne in opposition to the claim of Aegon II (the king’s eldest son from his second marriage). What followed is known as the Dance of Dragons — a protracted, brutal civil war between the factions supporting Aegon II and those supporting Rhaenerya. By the end of the dispute thousands had died including many of the Targaryen lineage. Nearly all of the Targaryen dragons perished during the Dance — either in combat or when a group of Kings Landing radicals rushed the Dragonpit.

A “dance” between Jon Snow and Daenerys seems unlikely, but could quickly become ferocious. Earlier in the episode Jon rode Rhaegal — a development that seemed inevitable given the dragon’s name. Dragons are fiercely loyal to their riders and while Daenerys might be Rhaegal’s mother, if it came to combat between the two Targaryen heirs Daenerys might find herself with only one dragon left on her side. Granted, she’d be at an advantage given Drogon’s superior size, but an airborne battle could easily leave both dragons (and their riders) mortally wounded.

Perhaps the best hope to avoid any dispute over succession is the possibility offered by Davos— Jon and Daenerys marrying and ruling side by side. The two would seem to complement each other well. Daenerys would provide the firm conviction Jon sometimes lacks and Jon could act as a check on Daenerys’ occasional “burn them all” impulses. With the Night King bearing down from the North and Cersei scheming in the South, a “dance” between Jon and Daenerys could spell doom for the realm.