Rhaenyra Targaryen

Queen Aemma dies in childbirth, and the baby doesn't survive either. Viserys breaks with his brother Daemon and does something new: he names Rhaenyra his heir and makes the lords of Westeros swear fealty to her. Soon after, he marries Alicent Hightower, Rhaenyra's best friend and the daughter of Otto, the Hand of the King. The friendship starts to sour.

As a teenager, Rhaenyra turns down every suitor her father brings. One night Daemon takes her through the streets of King's Landing in disguise. Afterward she spends the night with Ser Criston Cole of the Kingsguard. To kill the rumors, Viserys arranges her marriage to Laenor Velaryon, son of Corlys and Rhaenys. At the feast, Criston kills Laenor's companion, and Alicent shows up dressed in green, a sign that House Hightower is picking a side.

Ten years later, Rhaenyra has three sons, Jacaerys, Lucerys and Joffrey, all brown-haired and all looking a lot like Ser Harwin Strong. Rumors about their father become a weapon for the Greens, Alicent's side. Harwin and his father die in a fire at Harrenhal.

At Laena Velaryon's funeral on Driftmark, Alicent's son Aemond claims the dragon Vhagar. In the fight that follows, Luke cuts out his eye. Alicent goes at Rhaenyra with a knife. Rhaenyra and Daemon then fake Laenor's death so he can slip away, and the two of them marry.

Years later, Rhaenyra returns to King's Landing to defend Luke's inheritance and finds her father gravely ill. Viserys dies that night. Alicent takes his last words as a wish to crown her son Aegon, and the Greens rush to do it.

On Dragonstone, Rhaenyra hears the news, goes into labor and loses her daughter. Even so, her side, the Blacks, crowns her, and she chooses to seek alliances before going to war. She sends her sons out as envoys. At Storm's End, Aemond chases Luke on Vhagar, and Luke and his dragon Arrax are killed. Daemon brings her the news.

Rhaenyra searches for Luke's remains and shuts herself away in grief. Daemon acts alone and sends two killers, Blood and Cheese, into the castle. They murder Aegon's young son, and Rhaenyra blames her husband for it. Soon after, Ser Arryk Cargyll poses as his twin, Erryk, to kill the queen. Erryk gets there in time, and both brothers die.

Rhaenyra slips into King's Landing in disguise to talk with Alicent, with no result. After the battle at Rook's Rest, where Rhaenys dies, she decides she needs more dragons. She calls on the dragonseeds, bastards with Targaryen blood, and three of them claim mounts: Addam takes Seasmoke, Hugh takes Vermithor and Ulf takes Silverwing. At season's end, Alicent comes to Dragonstone and offers up the city. Rhaenyra answers that she'll only accept with Aegon dead.

The war reaches the sea and Jace dies in a naval battle, which leaves Rhaenyra shattered. She flies to King's Landing with her dragons, takes the city and sits the Iron Throne. Aegon has fled. Otto Hightower is brought before her, and Rhaenyra cuts off his head herself.

Early in her rule, she learns the rich were hoarding food while the people starved. She serves the nobles a banquet of rats and has the storehouses opened. She declares Aegon dead, but he turns up again. From then on, Rhaenyra hardens: when the High Septon refuses to anoint her, she has him killed. By season's end, Helaena, held in the castle, throws herself from a window.

In George R.R. Martin's Fire & Blood, the story comes through chroniclers who contradict each other, and Rhaenyra feels more distant. The show puts her at the center and makes Alicent her childhood friend; in the book, Alicent is quite a bit older. Milly Alcock plays young Rhaenyra in the first half of S1; Emma D'Arcy takes over as the adult.