Theon Greyjoy is a major character in the book series A Song of Fire & Ice and its television series adaptation Game of Thrones. He is the only surviving son of Balon Greyjoy and heir to the Iron Islands.
When he was a boy of nine, his father crowned himself King of the Iron Islands; this lead to a failed rebellion that resulted in Eddard Stark taking young Theon hostage back to Winterfell. Though he was there against his will initially, Theon grew to regard the Stark family highly and saw Robb Stark, Eddard's eldest son as his best friend.