Why Jon Snow has always been the 'rightful heir' to the Iron Throne

Warning: Spoilers ahead for the "Game of Thrones" season seven finale, "The Dragon and the Wolf."

The seventh season of "Game of Thrones" finally delivered irrefutable proof that Jon Snow is the son of Prince Rhaegar Targaryen and Lyanna Stark. Plus the series shocked viewers by revealing Jon's real name - Aegon Targaryen.

"He's never been a bastard," Bran said. "He's the heir to the Iron Throne."

Showrunner David Benioff reasserted this in one of the behind-the-scenes videos shared by HBO after the finale aired. When discussing Jon's legitimized parentage and his real name, Benioff said "That means he's the rightful heir to the Iron Throne. That changes everything."

Here's the Targaryen family tree, beginning with Daenerys and Rhaegar's father, the Mad King Aerys:

In typical Westerosi families, the line of succession follows the male line of descendants in order of birth.

So after the Mad King Aerys, Rhaegar Targaryen was next in line for the throne. Then after Rhaegar, the crown is passed to Rhaegar's eldest son. Since Jon is the only living male descendant of Rhaegar, he is the rightful heir to the throne.

Rhaegar's other son, also named Aegon, was ahead of Jon in the line of succession. But he was killed, along with their sister Rhaenys, during the sack of King's Landing at the end of Robert's Rebellion.

Daenerys only has a claim to the crown if Jon is eliminated from the line of succession. They are the only two surviving Targaryens.

As we explored after the season seven finale, this revelation about Jon's claim to the Iron Throne will likely be a contentious part of his and Daenerys' storyline in the eighth and final season of "Game of Thrones."

"Just as we're seeing these two people come together, we're hearing the information that will inevitably, if not tear them apart, cause them real problems in their relationship," showrunner D.B. Weiss said after the finale.

With the series coming to a close, more in-fighting between houses is the last thing we'd want to see. After all, the Night King just flew into Westeros on the back of an undead dragon with nuclear firepower capabilities. The focus should be on survival, not a new Targaryen civil war.

Plus, we've long theorized that nobody will sit on the Iron Throne at the end of the series, so does it even matter than Jon has the strongest claim? We'll have to wait for season eight to see where this revelation will take Jon.

In the meantime, learn more about Rhaegar and his relationship with both his father and Lyanna Stark in our exploration of everything we knew about the Dragon Prince.