(Note: This post contains tons of spoilers for “Game of Thrones.”)
At the end of “Game of Thrones” Season 6, quite a few people got wiped out. The massive wildfire explosion at the Sept of Baelor took out quite a few highborn characters who had been essential to the war — and cleared out a lot of the enemies of Cersei Lannister.
The majority of the people who got blown up in the Cersei’s Season 6 finale power move were members of House Tyrell, the powerful lords who came to the Lannisters’ aid against Stannis Baratheon and the Starks during the War of the Five Kings.
There was a reason why Lady Olenna, the Tyrell matriarch told Ellaria Sand in the Season 6 finale that “Cersei stole the future from me…survival is not what I’m after now.” Basically, at the end of Season 6, House Tyrell was going extinct. And in Season 7, it’s been fully eliminated.
House Tyrell found itself on the losing end of several attempts at making lasting alliances. The Tyrells first tried to ally with Renly Baratheon when he made his claim for the Iron Throne, but when Stannis assassinated Renly, Lord Mace Tyrell and the rest of the family allied with the Lannisters.
Margaery Tyrell pledged to marry Joffrey Baratheon in order to combine the two houses — the Lannisters needed the Tyrells’ wealth and troops to keep fighting the war — and Loras Tyrell was pledged to marry Cersei. But even by then, Cersei had started to become suspicious of the Tyrells and worked to undermine the family. Meanwhile, Margaery and her grandmother, Lady Olenna, began working to manipulate and control Joffrey.
When Joffrey was poisoned at his wedding (by Lady Olenna, in fact), the next in line for the king, Tommen Baratheon, was pledged to Margaery. But the subsequent death of Tywin Lannister meant that Cersei was no longer forced to marry Loras. Later, when Cersei restored the Faith Militant, the military arm of the religion in King’s Landing, Loras was arrested and charged with “buggery.”
Loras’ trial for homosexuality, and Cersei’s for adultery, were both set to take place in the Sept of Baelor. Instead of attending, Cersei stayed in the Red Keep and ordered a cache of wildfire beneath the sept ignited. The explosion destroyed the building with Loras, Margaery and Mace Tyrell inside.
That left Lady Olenna remains in House Tyrell, with seemingly no remaining known heirs now that Margaery and Loras dead. And in Season 7, the Lannisters attacked the Tyrell fortress Highgarden and captured it. Jaime Lannister poisoned Lady Olenna when he took the castle, effectively eliminating House Tyrell from Westeros. But she got the last word, telling Jaime about how she poisoned her son Joffrey. She said she wanted to make sure Cersei knew it was her.
If there are other Tyrells floating around who might inherit the family name, we haven’t seen them. That probably means that House Tyrell is gone — they lost the Game of Thrones.