House Greyjoy rules over the Iron Islands, a harsh and bleak collection of forbidding islands off the West Coast of Westeros, from the castle at Pyke. The Head of the House is Lord Reaper of the Pyke. The Greyjoys have traditionally survived by raiding their neighbours. They have always had plans to conquer the mainland. The Drowned God is the deity worshiped on the Iron Islands. This religion justifies the ironborn way of piracy and raiding.
Balon Greyjoy is the current Head of the House.
Balon Greyjoy launched the Greyjoy revolt nine years before the series begins with a view to securing independence from the Iron Throne. He is defeated.
Balon is married to Alannys of House Harlaw. They had four children of who two, Rodrick and Maron are dead.
Balon's remaining son, Theon who was 8 years old at the time, was taken as hostage by House Stark to ensure Balon's good behaviour.
Theon becomes a close friend of Robb Stark and is sent by him as an emissary to ask Lord Greyjoy to work together in gaining their independence. However, Theon turns on him and joins his father Lord Balon in his campaign to capture the North. He takes Winterfell and installs himself as Prince of Winterfell until he is betrayed by his own crew and delivered to House Bolton. At the end of season 3, Theon is held captive by Ramsay Snow (who is the bastard son of Roose Bolton who has been named Warden of the North for his part in killing Robb Stark). Ramsay sends Theon's penis in a box to Lord Pyke threatening to cut him up piece by piece until all the ironborn leave the North.
Yara Greyjoy is Theon's older sister. She has been raised by her father to be a fierce warrior commander of her own longship. When Lord Greyjoy refuses to help Theon, she disobeys her father and sails out to rescue her brother.
