Petyr Baelish

Petyr came to Riverrun at eight years old as a ward of Lord Hoster Tully, grew up alongside Catelyn, Lysa, and Edmure Tully, and fell in love with Catelyn in a way that never had anywhere useful to go. Edmure's mocking nickname for his small stature and his family's lands on the smallest of the Fingers stuck for life. He fought a duel for Catelyn's hand against Brandon Stark as a young man and lost badly, a scar and a humiliation he has spent the rest of his career making other people pay for in installments.

He rose through minor offices at court on wit rather than birth, and as Master of Coin proved able to fund a profligate crown through debt, favor-trading, and brothels held in his own name — a financial architecture the Iron Throne came to depend on and never fully understood, which was rather the point.

His fingerprints, mostly invisible until well after the fact, are on Jon Arryn's death, Eddard Stark's fall, and the poisoning of King Joffrey at his own wedding feast — the strangler venom he supplied and the frame he arranged both quietly served his ends and someone else's confession, tidily separated. He married the widowed Lysa Arryn, engineered her earlier crimes on his behalf, and pushed her through the Moon Door of the Eyrie once she had served her purpose, installing himself as Lord Protector of the Vale in the guardianship of her son.

He has since remade Sansa Stark as 'Alayne Stone,' his supposed natural daughter, and is building something in the Vale and beyond it that no other character in the published chronicle has yet been shown to fully understand.