Theon Greyjoy
From Asoiaf
Theon of House Greyjoy is the third son and fourth child of Balon Greyjoy, Lord of the Iron Islands and Lady Alannys of House Harlaw.
His older brothers Rodrik and Maron were both killed during Greyjoy's Rebellion leaving Theon as Balon's sole living son and heir.
Theon lives at Winterfell as the ward of Eddard Stark, Lord of Winterfell.