Spoilers ahead for the season-five finale of Game of Thrones.
House Baratheon is no more, and Stannis has only himself to blame.
Killing off the whole family line is a significant departure from the published books of A Song of Ice and Fire thus far. While George R.R. Martin may have certainly planned to have Stannis die, even to have his wife Selyse and his daughter Shireen die, it has not yet come to pass. Showrunners David Benioff and Dan Weiss have intimated that at least some of these deaths are upcoming arcs that Martin shared with them in plotting out the television series past the published works, but that doesn't mean these characters will die in the books in this succession, or under these circumstances. (Brienne, for instance, is in a different part of Westeros; Shireen and Selyse didn't accompany Stannis on the march to Winterfell.) The situation we're facing on the show is new territory. So, what does it all mean?
Fans freaked out when Stannis sacrificed his daughter Shireen in episode nine, burning her at the stake, but King Robert's true heir has never been one to care that much about his family line. Soon after we met him in season two, he killed his younger brother Renly via one of Melisandre's shadow babies. While killing Renly (and leaving witnesses) was Stannis's ultimate undoing, those weren't his only murders. He also sacrificed his brother-in-law, Ser Axell Florent, and tried to kill his nephew Gendry, the last living son of King Robert. As far as we know, Gendry is now the only surviving heir of King Robert, but he hasn't been legitimized.
The publicly recognized "son" of King Robert, King Tommen, meanwhile, is finding his own claim to the throne less secure by the minute. "Tommen shouldn't be there," actor Liam Cunningham, who plays Stannis’s devoted lieutenant Davos, told us. "He's a usurper." Tommen, too, has no heirs — his wife is not all that inclined to repeat the antics of their wedding night, and his siblings are dying like flies. (RIP, Myrcella.) Worse yet, he's not actually a Baratheon, and his mother Cersei's confessions and trials could mean Tommen will lose his crown, or even his head. Should Tommen die as well, the realm will fall into chaos. There is no clear line of succession.
This, more than anything, is Stannis's real crime. Part of being king is being protector of the realm, and while he got a good start as one of the only leaders (outside of Jon Snow) to take the threat of the White Walkers seriously, he ultimately failed. He got mired in distractions and ambition, just as his camp got mired in the snow. He killed off his heirs. Who can save Westeros from itself now?
"Any other show, you would say Dany," Cunningham said. "But it being Game of Thrones, it's up for grabs. Is it Ramsay who said last season, 'If you think this is going to have a happy ending, you haven't been paying attention'? I'm as interested as anyone to see what happens next. We're plummeting, racing towards the end of the story now."