(Spoilers ahead for the July 30 episode of “Game of Thrones,” “The Queen’s Justice.”)
The third episode of “Game of Thrones” Season 7, “The Queen’s Justice,” ended with a crushing blow by the Lannisters against their enemies. While Daenerys was capturing Casterly Rock, the Lannisters’ family stronghold, the Lannister army moved against Highgarden, the fortress held by Dany’s allies, the Tyrells.
It was a big victory for Jaime Lannister (Nikolaj Coster-Waldau), striking a big blow by eliminating Olenna Tyrell (Diana Rigg), a key ally to Daenerys (Emilia Clarke). But taking out the Tyrells was a secondary objective — after all, that house was basically already done for after Cersei blew up most of the family in the Season 6 finale.
No, the real objective was something far more pressing: to capture the castle, and the wealth, of one of the richest families in Westeros.
Cersei (Lena Headey) needs that money more than she needs to eliminate the Tyrell army (although Jaime managed to do that, too). Earlier in the episode, she met with a representative of the Iron Bank of Braavos, one of the richest institutions in the world of “Game of Thrones.”
The Iron Throne owes a ton of money to the Iron Bank, both because of the War of the Five Kings earlier in the show, and because of King Robert’s poor record with fiscal responsibility when he ruled. The bank is ready to write her off and invest its money in a different ruler in Westeros — until Cersei convinces them otherwise.
Cersei coaxes the Iron Bank into waiting to back Daenerys by mentioning her destruction of the slave trade in the Free Cities in Essos, something that’s undoubtedly cost the Iron Bank a load of money. But while the Lannisters are notoriously wealthy, they don’t actually have any real money. They got their wealth from a gold mine underneath Casterly Rock for years, but lent all of their wealth to the Iron Throne during Robert’s reign. Now that mine is empty, and they’re effectively broke, and haven’t been able to pay back the Iron Bank the massive amount that they owe.
But a Lannister always pays her debts. With Jaime capturing Highgarden, the Lannisters now control the wealth of the Tyrells, the richest family in Westeros at this point. And with that money, Cersei can pay back some of what she owes the Iron Bank, and show them that they should back her instead of her enemies.
It’s an important strategic move. If the Iron Bank chose to back Daenerys with its money instead of Cersei, she probably would lose the war just from the inability to feed her people and pay her soldiers. But with the Iron Bank on her side thanks to the money she just got from Highgarden, the situation is reversed: Now the Lannisters have more gold coming in, and Daenerys loses a key potential ally.
Meanwhile, the Lannisters have lost Casterly Rock, but Dany lost her fleet and lots of her Unsullied to take it. But at this point Casterly Rock is little more than a symbol, considering its mine has been barren for years.
Add to that the fact that Jaime just destroyed one of Dany’s armies, Euron (Pilou Asbæk) wrecked the Iron Fleet and all the ships Grey Worm (Jacob Anderson) used to get to Casterly Rock, and Cersei has Dornish leader Ellaria Sand in her dungeon, and it becomes apparent in Episode 3 that the Lannisters aren’t going to go quietly in this war. They’re still a major force to be reckoned with, even if Dany does still have her three dragons.