On page 683 of A Storm of Swords, King Joffrey finally bites the dust. Though no one was sad to see him go, his death left the readers with a bit of a puzzle--who really killed him?

The most obvious choice, as presented later in the book, is Olenna Tyrell, the Queen of Thorns. However, there are several other lesser suspects that are brought up from time to time, though they are almost certainly not responsible. These will be dealt with first, before looking at the evidence pointing to Olenna.

I. TYWIN LANNISTER

Cold, formidable and not one to be slighted, Tywin seems like just the man to murder his own grandson at his wedding feast. But where is the motive?

It comes on page 593 of A Storm of Swords. Joffrey has just been dismissed from the small council after mocking Tywin for supposedly fearing Aerys.

“The boy is thirteen. There is time yet.” Lord Tywin paced to the window. That was unlike him, he was more upset than he wished to show. “He requires a sharp lesson.”

Tyrion had gotten his own sharp lesson at thirteen. He felt almost sorry for his nephew. On the other hand, no one deserved it more.

This speech of a ‘sharp lesson’ could very well foreshadow Joffrey’s death. But upon closer examination, the quote appears to be more of a red herring than anything else. Though rather platonic toward his family, Tywin never seems like the man to become a kinslayer. Even when Tyrion is accused of killing Joffrey, Tywin tells him that he would rather see Tyrion on the Wall than executed. And though upset, Tywin appears far more logical than being reduced to poisoning his grandson over some petty slight. All in all, the motives don’t match the character. There is no further evidence pointing toward Tywin, and quite a lot to the contrary.

II. TYRION LANNISTER

Tyrion was accused and found guilty of murdering his nephew. But did he really do the deed? There are some pieces of evidence, but many more to the contrary.

1) The Motive--Bran’s attempted assassination

The morning before the wedding, Tyrion presents Joffrey with a wedding gift that is rather ill-received. Proclaiming that he ‘is no stranger to Valyrian steel,’ Joffrey takes his new sword Widow’s Wail and proceeds to cut Tyrion’s gift into pieces, then demands a new one. At this point, Tyrion undergoes a slight epiphany.

“You and Lady Sansa owe me a batter present, Uncle Imp. This one is all chopped to pieces.”

Joff gave him a sharp look...

---pg. 664, A Storm of Swords.

This dagger Tyrion is referring to is the one that the assassin used to try and kill Bran as he slept, Valyrian steel with a dragonbone hilt. (A Game of Thrones, pg. 136). Tyrion has just realized that it was Joffrey who sent the cutthroat, and is subtly telling Joff that he knows.

However, Tyrion later worries over what Joffrey might do because of what he discovered:

He squirmed uncomfortably. He ought to have held his tongue at breakfast. The boy knows now. My big mouth will be the death of me, I swear it.

---pg. 668, A Storm of Swords.

We can conclude that Tyrion was worried that Joffrey would try and kill him over what he knew about the boy’s role in Bran’s attack. This suggests that Tyrion had a motive in Joffrey’s murder. However, from other information we have, it seems clear that Tyrion is not the murderer.

2) The Drained Chalice

His eyes fell on the wedding chalice, forgotten on the floor. He went and scooped it up. There was still a half-inch of deep purple wine in the bottom of it. Tyrion considered it for a moment, then poured it on the floor.

---pg. 684, A Storm of Swords.

This is quite a curious action, and will later be used against him in the trial. But why did he do it?

The answer is relatively simple. Later in A Storm of Swords, on page 736, Tyrion thinks to himself that Sansa probably killed Joffrey. When Tyrion drained the chalice, he was trying to protect Sansa from being found guilty. As Jaime says, Tyrion “gets these fits of gallantry from time to time.”

3) Tyrion’s “Confession”

On page 874 of A Storm of Swords, an enraged Tyrion tells Jaime that he did kill Joffrey. Yet this confession is a lie brought upon by Tyrion’s anger, and is clearly false. In many other places throughout the book (most notably on page 736, as noted above), Tyrion’s thought processes make it clear that he did not poison Joffrey. The only possible explanation would be if Tyrion suffered a memory lapse after putting in the poison, an event that seems extremely unlikely.

III. OLENNA TYRELL

On page 769 of A Storm of Swords, Littlefinger tells Sansa quite a lot about the political situation in King’s Landing, including who killed Joffrey--Olenna Tyrell, the Queen of Thorns. While Littlefinger is not known as the most honest of men, it seems likely that he is telling the truth. Why?

1) The Motive--Margaery’s Safety

Littlefinger tells Sansa that Olenna’s motive for killing Joffrey was so Margaery would become a queen without risking Joffrey’s crazed notion of justice and angry beatings. Certainly, GRRM seems to have been leading up to this. Earlier in the book, Olenna and Margaery spoke with Sansa about what a monster Joffrey was, and did not seem surprised by what Sansa had to say...almost as if they already knew, and were simply confirming the tale. Yet strangely, Olenna does not seem to fear for her granddaughter’s safety at all.

So yes, Olenna’s motive certainly fits better than Tywin’s or Tyrion’s, and has enough evidence to support it.

2) The Hairnet

Littlefinger tells Sansa that the poison came from a jewel on Sansa’s hairnet. This appears quite likely to be the case for several reasons.

On page 743 of the book, Maester Ballabar and Maester Frenken confirm at Tyrion’s trial that a throat-constricting poison was used to kill Joffrey. In the series thus far, we only know of one such poison...the Strangler. On page 20 on A Clash of Kings, Maester Cressen makes the Strangler out of crystals strikingly similar to those on Sansa’s hairnet--small and colored deep purple. It comes from a leaf grown near Asshai. And, coincidentally, on page 914, Dontos gives Sansa the hairnet and says the crystals are from Asshai.

So it seems the Strangler was the weapon used. But did Olenna use it? It seems quite likely. On page 672 of A Storm of Swords, Olenna does come and straighten Sansa’s hairnet, giving her a prime opportunity to grab a crystal. And she does...on 686, Sansa notes that one crystal is missing from her hairnet. And Olenna certainly had a chance to drop in it Joffrey’s drink...on page 681, she comes tottering up with Margaery to talk while Tyrion is pouring Joffrey’s wine.

Just as one last confirmation, we have a third-party who also states it was the Strangler in Sansa’s hairnet that killed Joffrey...though not so directly. As the Ghost of High Heart prophecizes on page 491:

“I dreamt of a maid at a feast with purple serpents in her hair, venom dripping from their fangs...”

The dream matches Joffrey’s murder exactly.

The only question is why Olenna bothered with snatching a jewel from Sansa’s hairnet in the first place, instead of carrying it to the feast herself. There is really no explanation for this, except that maybe that Olenna wanted somebody to pin the murder on in case they discovered it was the Strangler that had killed Joffrey. The fact that Olenna wanted Sansa to come to Highgarden after Joffrey’s wedding shows that, while she may have framed Sansa, it was as a last resort only, and she certainly didn’t want anyone to suspect her.

Another possible explanation comes from Cressen’s thoughts on page 21 of A Clash of Kings. Cressen reflects how the process to make the Strangler is long and tedious. Perhaps Littlefinger knew a man who made the poison...but the process was time-consuming. By the time it would be done, Olenna would be in King’s Landing, and Littlefinger would have no way to get the poison to her without Varys’s spies watching. The only way was to make an inconspicuous exchange via the hairnet.

3) Was Littlefinger Involved?

It seems quite likely that Littlefinger is partially to blame for murdering Joffrey, and that he was in cohoots with Olenna. He certainly had time at Bitterbridge to plan such a murder with her...and implies as much, while talking with Sansa. Also, it was Dontos that gave Sansa the hairnet with the Strangler in it. Since Dontos was under Littlefinger’s employ, it seems likely that Littlefinger gave Dontos the hairnet to pass along to Sansa, in order for Olenna to be able to use it.

Also, Littlefinger tells Sansa on page 768 of A Storm of Swords that he knows the murderer was the one who straightened out Sansa’s hairnet. How could he known this if he was not present at the feast? The only possible explanation is that he and Olenna had already planned it ahead of time.