Garrick Grayburn is an unseen character in Game of Thrones. Despite being deceased several years before the story begins, he will appear in a flashback in Season 6. He is mentioned in the first, second, third, and fourth seasons. He is the father of both Hendrick and Kormed Grayburn, thus making him the grandfather of Carmine, Madelynne, Ariana, and Konrad Grayburn.
Lord Garrick was the Lord of Brightbank during both Robert's Rebellion and the Greyjoy Rebellion. He was a renowned soldier and battle commander and was known for his strategic mind. He was killed in battle by Tyrus Harlaw during a duel that took place during the Siege of Pyke, the final battle of the Greyjoy Rebellion. Because of this and his other numerous heroics during the Greyjoy Rebellion, he was posthumously dubbed "Ironbreaker".