Despite Tywin Lannister’s low opinion of his youngest son, in seven seasons of Game of Thrones, Tyrion Lannister has fought and won his fair share of battles. Leaving aside the Season 1 Battle of the Green Fork (where he was knocked out and never recovered), Tyrion can take pride in his involvements in both the Battle of Blackwater Bay and the Battle of Fire. In both cases, his side won. But in Season 7, Episode 3, “The Queen’s Justice,” Tyrion will wage the most important battle of his life against the specter of his dead father.
Scenes from the Episode 3 trailer (as well as Tyrion and Grey Worm’s stated plans in Episode 2) have prepared fans to watch Tyrion Lannister’s dispatch an army of Unsullied try to take back the ancestral family home.
Though Tyrion is now trying to conquer the Rock for his queen, Daenerys, long-time fans of the show may remember that after his victory at Blackwater in Season 2, the former Hand of King Joffrey tried simply asking his father, Tywin, if he could take possession of the castle. With the older Lannister heir, Jaime, in the Kingsguard and unable to inherit, Tyrion was, by right, next in line. You may have expected Tywin to be frosty in the face of that request; instead he was downright arctic.
When Tyrion asked him why his request was being denied, Tywin trampled all over his son in a devastating Season 3 scene:
So, clearly, Tyrion has something to prove here. But if you’ve read the Song of Ice and Fire books by George R.R. Martin, you know that the importance of Casterly Rock goes even deeper. Remember, this is the ancestral family home of the Lannisters so Casterly Rock is to Tyrion what Winterfell is to any given Stark. His childhood may not have been full with as many (or any) happy memories, but in the books, Tyrion refers to Casterly Rock as a part of his identity. “Stone, I must be stone,” he tells himself in A Clash of Kings. “I must be Casterly Rock, hard and unmovable.”
The Rock has been mentioned early and often in both the book and the show. Cersei even makes reference to it in her very first line for the HBO series . . .
. . . but it has never resonated with fans quite the same way that Winterfell or a number of other ancestral homes have, likely because neither the books nor the show have ever set a scene there. (Though Martin has said multiple times that Casterly Rock will appear some time before the saga is over.)
And as hard as it was for Tywin to imagine giving Tyrion Casterly Rock, he never could have conceived of his younger son taking it. Casterly Rock is a famously impenetrable castle that has never been breached by a standing army. (Though it was breached once before. More on that in a bit.) Even the dragonriders of Aegon’s Conquest only got the Lannisters to bend the knee after defeating them in battle, which was a relief to the Targaryens, who feared Casterly Rock might even be dragonfire-proof.
Back in Season 3, when he was planning a conquest of the Rock himself, Robb laid out what a tricky task taking the Lannister seat would prove.
The cliffside castle is bound by water on the west and allied territory on the east. Tyrion can’t exactly march through King’s Landing to attack Casterly Rock. And he also has to contend with the fact that the waters on the shores of Lannisport are now extremely vulnerable to any of Euron Greyjoy’s men still lingering around the Ironborn home base of Pyke, just north of the Rock.
As Jaime Lannister helpfully reminded audiences in Season 7, Episode 1, Euron burned all the ships docked in Lannisport during the Greyjoy Rebellion. And Tyrion’s men will have had to sail all the way around the south of Westeros in order to take the Rock. They’re a long way from Dragonstone’s ability to help there.
But, of course, Tyrion has an advantage in all this. His men don’t have to take Casterly Rock by land, or by a full frontal naval attack. As he told Varys back in Season 2, Tyrion was put in charge of the sewers—a route the Unsullied are familiar with—of Casterly Rock when he was just a young man . . .
. . . and the only person to ever take Casterly Rock was someone called Lann the Clever. According to legend, Lann broke into the Rock by squeezing himself through a narrow, secret entrance. As Martin wrote in The World of Ice & Fire: “Once inside, he began to whisper threats in the ears of sleeping Casterlys [the family that lived there at the time], howling from the darkness like a demon, stealing treasures from one brother and placing them in the bedchamber of another, rigging snares and deadfalls. Thus, he set the Casterlys at odds with one another and convinced them their seat was haunted.” Lann then took the castle for himself.
That sounds exactly like the kind of thing Tyrion would do, and even if his ultimate plan is nowhere near that involved, any and all link between Lann the Clever and Tyrion would further incense Tywin Lannister if he were still around. Lann the Clever is the founding member of House Lannister, and Tywin’s favorite subject was how Tyrion didn’t belong as a member of the family. But Tyrion the Clever is most definitely (probably) a Lannister through and through.
Though Tywin Lannister died way back in Season 4 (or book 3), Casterly Rock still stands as a testament to the legacy he built. In A Dance with Dragons one of the Sand Snakes, Nymeria, sees it as the last piece they need to knock over in their war against the Lannisters. “It ends,” she says, “when Casterly Rock is cracked open, so the sun can shine on the maggots and the worms within. It ends with the utter ruin of Tywin Lannister and all his works.” Little did Tywin ever suspect that it would be his own son—the man he always underestimated—who might prove the greatest threat to the Lannister legacy, and the key to cracking Casterly Rock from the inside.
