Rhaelle Targaryen

Daughter of King Aegon V, sent to Storm's End as a girl and married to Ormund Baratheon. She is the quietest figure in this entire story and arguably the most important: every legal argument for Robert's kingship runs directly through her.

The irony is thorough. Robert spent his life hating Targaryens with a heat that never cooled, and the throne he took was his to claim only because his grandmother was one. It also made him and Rhaegar cousins, which means the war that defined him was, at bottom, a family quarrel — a fact he would have thrown a cup at you for pointing out.