Even though I am a devout fan of Daenerys Targaryen, I also am analyzing the other factions in the War of the Five Kings. With this in mind, I will be addressing the possible future for House Lannister in Season 7. Cersei Lannister’s destruction of the Sept of Baelor has resulted in dire consequences for House Lannister. To begin with, the Sept of Baelor was the center of worship for the Faith of the Seven, making it the Game of Thrones equivalent of the Vatican. With it destroyed, there will be serious social and religious consequences. For instance, because the Faith of the Seven was the dominant religion in Westeros, every follower, rich and poor alike, will hate the Lannisters more than ever and rise up against them. When an uprising happens, the Lannisters will not have the numbers to maintain their hold of the Iron Throne due to their losses during the War of the Five Kings and the loss of House Tyrell’s support.
The loss of House Tyrell’s support was the crippling blow to the Lannisters’ regime for three very good reasons. First, because House Tyrell commanded the largest army in Westeros of 100,000 men, which gave the Lannisters a numerical advantage against all their enemies. Second, House Tyrell is the richest family in Westeros second only to the Lannisters and without the Tyrell’s money, the Iron Throne’s ongoing debt crisis with the Iron Bank of Braavos will get worse. Third, the Tyrell’s territory is the most fertile land in Westeros, which allowed them to feed King’s Landing up until now so the Lannisters and their citizens are going to starve to death. Ultimately, the loss of House Tyrell also cost the Iron Throne the fealty of the Reach, the most populous region in Westeros.
The Tyrells are not the only allies the Lannisters have lost after Season 6. After the Red Wedding, they had House Frey governing the Riverlands and House Bolton governing the North. Now that House Bolton is extinct and House Frey is in disarray after Walder Frey’s death, the Lannisters have lost control over both the North and the Riverlands. Also, Dorne has withdrawn its fealty to the Iron Throne as well while the Iron Islands have declared independence. Due to these factors, the Lannisters only have control over the Westerlands, Stormlands, and Crownlands. This leaves the Lannisters without any allies or support of any kind, making their rule very fragile and unstable.
As for House Lannister itself, since Cersei’s wildfire plot annihilated her cousin and uncle, she, Jaime, and Tyrion are now the sole survivors of the main Lannister bloodline. This means that if anything happens to any of them, Casterly Rock and everything that comes with it will be inherited by one of their cadet branches. The thing about House Lannister is that because they are such an ancient family, they have developed countless relatives and cadet branches of the main bloodline over the centuries. This will make it impossible for House Lannister to be truly exterminated. So whatever happens one of these cadet branches may be left to pick up the pieces of their family’s legacy.
Now that Cersei Lannister has been crowned Queen of the Iron Throne, her megalomania and lust for power is going to increase. The more power she obtains, the more obvious her insanity, the more aggressive her subjects become. Her wildfire plot may have wiped out her enemies, but it also gave her many more enemies and undid all of Tywin Lannister’s good work, destroying House Lannister’s reputation and future. She is so shortsighted that she can’t even see the long term consequences of her actions. Her wildfire plot was also a clear indication that she will become just as bad as the Mad King if not worse. Cersei’s only redeeming trait was her love for children, but now they are all gone so now she is completely unhinged and unable to control her cruel and ambitious impulses. With Tyrion and Daenerys on their way, Cersei will believe that Daenerys is the queen who is foretold to overthrow her and will be hell-bent on stopping her even though Cersei no longer has the numbers and resources to stop Daenerys, which will hasten Cersei’s downfall. Also, when Jaime finds out that Cersei murdered their uncle, cousin, and indirectly their son, things will get ugly between them.
As the War of the Five Kings comes to a close, House Lannister will be attacked from the south, west, and possibly the north. With the Iron Islands building a new fleet, they will be able to strike Lannister territory from the coast along the Westerlands, which will further weaken the Lannisters’ power base. With help from the Vale, House Stark has rebuilt its military and is now capable of fighting House Lannister on even footing if they decide to invade the south. However, the greatest threat to Lannister rule will come from the south in the form of Daenerys Stormborn of House Targaryen. Daenerys commands the largest and most powerful army in the known world so she will easily demolish the weakened Lannister armies when she lands. Because they will be attacked from every direction, House Lannister is not going to survive what is coming and their reign will be as good as over.