Joffrey Baratheon
Crown prince and heir to the Iron Throne, a golden boy of twelve with a cruel streak his mother indulges and his father ignores.
A soul of House Lannister, born at King's Landing.
The fuller tale
Season One
Robert's heir in name, blond in a family of black-haired Baratheons, and the first thread anyone pulls on the way to what Cersei and Jaime have done. He is a boy raised to believe that wanting a thing is the same as being owed it: he goads Arya into a fight by the Trident, lets Mycah die for it, and stands over Ned in the throne room to take back a promise of mercy in front of the crowd he wants clapping. Robert's death makes him king before he has learned to fear anyone, and the first thing he does with the crown is take Ned Stark's head, live, with Sansa watching, because he likes how it looks.
Season Two
King now, and delighted by it in ways that curdle fast: he has Sansa beaten for her brother's victories and stripped in open court until Tyrion intervenes, and marks his name day with a joke that leaves men dead in the yard. He wants the wildfire that burns Stannis's fleet to be his own idea and lets Tyrion do the actual thinking behind it. When the city turns on him during the bread riots he takes a handful of filth to the face and remembers exactly who was standing next to him — not fondly. At Blackwater he watches the battle from the walls with his uncle for as long as it looks like winning, then goes to hide in his mother's rooms the moment it stops.
Season Three
Betrothed now to Margaery Tyrell, who manages him so smoothly he mistakes her indulgence for admiration, and furious that Sansa has been married off to Tyrion rather than left for him to torment on his own schedule. When word reaches King's Landing of the Red Wedding, he brings Sansa a book of the realm's great kings so he can walk her through an illustration of her brother's death, page by page, because taking things from people is the only intimacy he understands. Tyrion's wedding gift to him is a book too, on the reigns of past kings; Joffrey does not appreciate being outmaneuvered at his own game, and says so, loudly.
Season Four
His wedding to Margaery is the biggest show King's Landing has staged in years, and he spends it needling Tyrion in front of the whole court — makes him cupbearer, pours wine over his head, restages the War of the Five Kings with dwarfs for entertainment — because it is the last day he will ever get to be the smallest cruelty in the room. He chokes on his own wedding wine partway through the pie course, claws at his throat in front of five hundred witnesses, and dies in his mother's arms with his eyes full of blood, one finger pointed at his uncle.
Season Seven
Olenna Tyrell drinks Jaime's painless poison and confesses to Joffrey with her last breath.
How it ends for them
On the screen. Poisoned at his wedding (S4·E2)
The boy king was poisoned with the Strangler at his own wedding feast, purpling and clawing in his mother's arms. The Queen of Thorns and Littlefinger had arranged it between them; Tyrion was handed the blame and Sansa the escape.
On the page. The Strangler in his wedding wine (ASOS, ch. 61)
At his own wedding feast the boy king choked purple on poisoned wine — the Strangler, worked into a hair-net's black amethysts by the Queen of Thorns while everyone watched the dwarf. Tyrion got the blame; Littlefinger got Sansa.
He dies at his own wedding feast, in front of everyone, and both tellings agree on nearly every detail. The poison is the Strangler, a rare crystal that closes the throat; it reaches his wine in the chaos of the feast, and the boy king goes from mockery to clawing, purpling asphyxiation in the space of a song, dying in Cersei's arms while she screams for help that cannot come. His last act in both versions is to point at Tyrion, who had handled his cup — and Cersei's grief becomes an arrest warrant on the spot. The plotters, revealed to viewers and readers only afterward, are Olenna Tyrell, who would not let her granddaughter marry that, and Petyr Baelish, who supplied the poison in a hair-net of black amethysts and needed the chaos: the murder is a joint venture between the realm's two best players, and the realm's worst king never sees either hand. In the books the mechanism is identical, with the added cruelty that Tyrion later cannot stop turning it over — the pie, the cup, the moment — while dying convicted of it. Joffrey's death purchases nothing good for anyone: it sends Sansa into Littlefinger's keeping, Tyrion to a show trial, and the crown onto the head of a little brother who never wanted it.
Their chapters, book by book
A Game of Thrones 6 chapters that name them
Eddard I
Robert comes to Winterfell; in the crypts before Lyanna's statue he asks Ned to be his Hand and offers Joffrey for Sansa.
Sansa I
By the Trident, Joffrey's cruelty and Arya's temper collide; Nymeria bites the prince and is driven off with stones, and the lie begins.
Sansa IV
Summoned before the queen, Sansa writes the letters they dictate and pleads for her father's life on her knees before Joffrey's court.
Sansa V
Joffrey's first court: Barristan Selmy is stripped of his cloak, Janos Slynt is raised, and Sansa is promised mercy for her father — if he confesses.
Arya V
On Baelor's steps Ned Stark confesses to treason to save his daughters; Joffrey wants a head anyway. Yoren grabs Arya in the crowd: “boy.”
Sansa VI
Joffrey shows Sansa her father's head on the walls and promises her Robb's next; the Hound's rough counsel keeps her alive on the battlements.A Clash of Kings 3 chapters that name them
A Storm of Swords 5 chapters that name them
Where the page and the screen part
Book and show Joffrey are the same boy at different volumes. The novels age him down — twelve at his accession, dead at thirteen — and keep more of Robert's shadow on him: the story of Joffrey cutting open a pregnant cat to see the kittens, and Robert striking him for it, does the books' explaining, while the show trusts Gleeson's face. Television also gives him inventions the page never staged, most notoriously the crossbow murder of Ros and the on-screen beatings of Sansa, where the books keep his cruelty largely delegated — he has the Kingsguard do it, which the novels present as its own kind of cowardice. One book detail the show dropped entirely: it is heavily implied Joffrey, not any adult schemer, sent the catspaw with the Valyrian dagger to finish Bran Stark, having overheard Robert say the boy would be better off dead — meaning the entire War of the Five Kings traces back to Joffrey twice.
Their journey
Where the two tellings send them to the same place the road runs whole; where they part, the screen keeps the left and the books the right.