Lyanna Stark

By every surviving account, Lyanna rode harder, argued louder, and cared less for a lady's needlework than her father thought proper for a Stark daughter promised to a Baratheon lord. Robert Baratheon, betrothed to her since childhood in a match meant to bind North and Stormlands together, loved an idea of her that those who knew her best say never quite matched the woman herself. She and her brother Eddard shared a closeness he carried the rest of his life like a wound that would not close.

At the tourney of Harrenhal in 281 AC a mystery knight calling himself the Knight of the Laughing Tree unhorsed three lords who had been mistreating a squire, then vanished before the tourney's end rather than reveal his face; readers and characters alike have long suspected Lyanna beneath that armor, though the text supplies no confirmation either way. That same tourney, Prince Rhaegar Targaryen crowned her queen of love and beauty in front of the realm.

Lyanna disappeared not long after, and her disappearance — laid at Rhaegar's feet by an already furious King Aerys — became one of the sparks of Robert's Rebellion. She was found only at the war's end, in a tower in Dorne's red mountains, dying of a difficult birth, guarded by three Kingsguard knights who died rather than let Eddard Stark pass.

Ned reached her in time only to hear her extract a promise from him, its exact wording never given on the page, sworn in a bed 'smelling of blood and roses.' He kept whatever it was for the rest of his life, at the cost of his own marriage's honesty, and never spoke it aloud to anyone the chronicle lets us hear.